Mary Berry French Onion Soup With Mustard Cheese Croutes Recipe [Tips & Tricks]

If you’re craving a warm, comforting dish with a twist, Mary Berry’s French Onion Soup with Mustard Cheese Croutes is the recipe you need to try!

This delightful take on the classic French onion soup offers layers of rich, savory flavors, with sweet caramelized onions and a hint of tang from the mustard-infused cheese croutes. The golden, cheesy topping perfectly complements the deep, hearty broth, making every spoonful an absolute treat. Plus, Mary Berry’s recipe is simple enough for home cooks of all levels, so it’s a great way to impress your friends or family with minimal effort!

Mary Berry French Onion Soup With Mustard Cheese Croutes Recipe

Ingredients Needed

To prepare Mary Berry’s French Onion Soup with Mustard Cheese Croutes, you’ll need a combination of simple, yet flavorful ingredients that come together to create a rich, comforting dish. Let’s break it down:

1. Onions: The star of the dish, you’ll need a generous amount of onions-typically 4-6 medium onions, which should be thinly sliced. The onions will be caramelized to form the sweet, savory base of the soup. Yellow or brown onions are ideal, as they balance sweetness with a mild sharpness.

2. Butter: A rich, creamy element used to cook the onions and create a smooth, buttery texture in the soup. You’ll need around 50g (about 4 tablespoons) of unsalted butter to get the right consistency and flavor.

3. Olive Oil: A small amount (roughly 2 tablespoons) of olive oil will be used in combination with butter to prevent the butter from burning and to give the soup a richer depth of flavor.

4. Garlic: One or two cloves of garlic, finely chopped, add a lovely aromatic touch and enhance the savory profile of the soup. Garlic complements the caramelized onions beautifully, bringing out their sweetness.

5. Beef Stock: To create the rich, umami-packed broth that is the heart of French onion soup, beef stock is essential. Ideally, use homemade or high-quality store-bought stock for a deep, savory flavor. About 1 liter (or 4 cups) is required.

6. White Wine: A small amount (around 100ml) of dry white wine is added to deglaze the pan after the onions have caramelized. The wine gives a nice acidic balance to the soup, cutting through the richness and adding depth to the flavor profile.

7. Thyme: Fresh thyme sprigs bring an earthy, herby flavor that works harmoniously with the onions. About 2-3 sprigs should be enough to infuse the soup.

8. Bay Leaves: A couple of bay leaves are essential for adding a subtle, herbal flavor to the soup. They infuse the stock with their fragrant aroma as the soup simmers.

9. Salt and Pepper: Simple seasoning is key here. Adjust to taste, as the soup needs only modest salt and pepper, especially with the savory depth of the stock.

10. French Bread: For the croutes (toasties), you’ll need slices of sturdy French baguette or country-style bread. These will be toasted and placed atop the soup, providing a delightful crunch that contrasts with the smoothness of the broth.

11. Gruyère Cheese: A generous layer of Gruyère cheese is a classic component of French onion soup. Its nutty, slightly tangy flavor, when melted, creates a golden, bubbling crust that completes the dish.

12. Mustard: A subtle twist in Mary Berry’s version comes from Dijon mustard. The mustard is spread on the bread before adding the cheese, lending a tangy kick that cuts through the richness and adds an extra layer of flavor.

Equipment Needed

Mary Berry’s French Onion Soup with Mustard Cheese Croutes is relatively straightforward to prepare, but there are a few key tools that will help make the process easier and more enjoyable.

1. Large Soup Pot or Dutch Oven: A heavy-duty pot, preferably a Dutch oven, is perfect for this dish. Its ability to distribute heat evenly will help you caramelize the onions without burning them, and it’s large enough to hold all the ingredients when it’s time to simmer the soup.

2. Wooden Spoon: For stirring the onions as they caramelize, a wooden spoon is ideal. It prevents the onions from sticking to the bottom of the pot and gives you more control over the gentle stirring process.

3. Sharp Knife and Cutting Board: Thinly slicing the onions requires a sharp knife. A good-quality chef’s knife will make the task much easier and ensure the onions are sliced evenly, which helps them cook uniformly.

4. Ladle: Once the soup is ready, a ladle will make serving much easier, allowing you to pour the rich broth into bowls without spilling.

5. Baking Tray: For making the croutes, you’ll need a baking tray to toast the bread and melt the cheese in the oven. It’s essential that the tray is large enough to accommodate the slices of bread with cheese on top.

6. Grater: A fine grater is necessary for shredding the Gruyère cheese, ensuring it melts evenly and forms that perfect golden, bubbly crust.

7. Soup Bowls: Traditional French onion soup is served in shallow bowls, often oven-safe, so you can place them in the oven to finish the dish with the melted cheese. Make sure the bowls are sturdy enough to handle the heat.

How To Make Mary Berry’s French Onion Soup With Mustard Cheese Croutes

Making Mary Berry’s French Onion Soup is a simple yet satisfying process that requires patience to achieve the perfect caramelization of the onions. Here’s a step-by-step guide:

1. Caramelize the Onions: Start by heating a large pot over medium heat. Add the butter and olive oil. Once melted, add the sliced onions and cook them slowly for about 25-30 minutes, stirring occasionally. The goal is to soften them and develop a deep golden-brown color, which will bring out their natural sweetness.

2. Add Garlic and Wine: When the onions are perfectly caramelized, add the garlic and cook for another minute, just until fragrant. Then pour in the white wine, scraping up any bits from the bottom of the pot. Allow the wine to reduce by about half.

3. Add Stock and Herbs: Pour in the beef stock, add the thyme and bay leaves, and season with salt and pepper. Stir to combine and bring the mixture to a boil. Once it starts boiling, reduce the heat and let the soup simmer for 20-30 minutes, allowing the flavors to meld together. Taste and adjust seasoning if necessary.

4. Prepare the Croute: While the soup simmers, preheat your oven to 180°C (350°F). Arrange slices of French bread on a baking tray, and spread a thin layer of Dijon mustard on each slice. Top with a generous amount of grated Gruyère cheese. Bake for 10-12 minutes, or until the bread is toasted and the cheese is melted and golden.

5. Serve the Soup: Remove the bay leaves and thyme sprigs from the soup. Ladle the hot soup into oven-safe bowls, leaving enough space for the croute to sit on top.

6. Finish with Croute: Place the toasted, cheesy bread on top of the soup in each bowl, then place the bowls under a broiler for 3-5 minutes, or until the cheese is bubbling and slightly browned. Serve immediately.

Expert Tips

• Patience is Key for the Onions: The key to the perfect French onion soup lies in the caramelization of the onions.

  Don’t rush this step!

  The longer you allow the onions to cook, the more depth and sweetness they’ll develop. If they start to stick to the pan, lower the heat and add a splash of water to deglaze.

• Use Quality Stock: Stock is the backbone of the soup, so opt for high-quality beef stock or make your own. Homemade stock will provide a richer, more complex flavor that elevates the whole dish.

• Bread and Cheese: Don’t skimp on the quality of the bread or cheese. The bread should be sturdy enough to hold up to the soup’s liquid without getting soggy too quickly, and the cheese should melt beautifully. Gruyère is the traditional choice, but you can mix in some Emmental for a slightly milder flavor.

• Adjust the Mustard: Mary Berry’s mustard twist is subtle but impactful. If you love mustard, feel free to spread a slightly thicker layer on the bread to give it more punch. If you prefer something milder, use less mustard or opt for a sweet variety.

Mary Berry’s French Onion Soup with Mustard Cheese Croutes is a perfect blend of simplicity and sophistication. The deep, savory richness of the caramelized onions paired with the tangy mustard cheese croutes creates a balanced and comforting dish that is ideal for chilly evenings.

The slow-cooked onions bring out their natural sweetness, while the Dijon mustard adds a surprising, piquant twist to the classic recipe. By following the detailed steps and expert tips, you’ll be able to create this heartwarming dish that’s sure to impress friends and family alike. Whether you’re serving it for a cozy family dinner or as an elegant appetizer for a special gathering, this French onion soup will undoubtedly become a beloved favorite.

Easy Recipe Variations For Mary Berry’s French Onion Soup With Mustard Cheese Croutes

Mary Berry’s French Onion Soup with Mustard Cheese Croutes is already a delightful, rich, and comforting dish, but the beauty of it lies in its versatility. There are plenty of ways to tweak and experiment with the ingredients and methods to suit your personal preferences or dietary needs. Whether you’re looking for a twist on flavor, a quicker method, or a more indulgent variation, here are some easy variations to try:

1. Cheese Swap

The mustard cheese croutes are a star in this dish, but you can easily switch up the type of cheese used. While the tangy mustard cheese adds a lovely sharpness, try incorporating Gruyère for a nuttier, meltier option or a classic Swiss cheese for a more subtle flavor. If you enjoy a more intense flavor, a combination of aged cheddar and blue cheese could add a delightful depth.

2. Vegan French Onion Soup

If you’re looking to make this soup vegan-friendly, the transition is simple. First, replace the butter with olive oil or vegan butter.

For the cheese croutes, try using a vegan cheese alternative, such as a vegan Gruyère-style or mozzarella-style cheese, which can melt beautifully over the soup. Additionally, make sure to swap the stock for vegetable broth instead of beef stock to maintain that hearty flavor.

3. Herb Variations

While the recipe may call for thyme, French onion soup offers a great opportunity to experiment with other herbs. Try adding a few sprigs of rosemary for a fragrant, woodsy twist, or sprinkle some fresh parsley or basil for a pop of freshness. If you enjoy a bit of heat, a pinch of crushed red pepper flakes or some fresh chili slices can be a great addition, adding a little zing to the soup.

4. Caramelized Shallots And Garlic

The beauty of French onion soup is in its caramelized onions, but you can also add shallots or even roasted garlic for an extra layer of sweetness and richness. Shallots are milder and sweeter than onions, which can contribute a subtle depth to the overall flavor. Roasting garlic gives it a sweet, mellow profile, which can add an additional dimension to the base of the soup.

5. Quick Weeknight Version

If you’re pressed for time, you can still enjoy a satisfying French onion soup without spending hours on caramelizing the onions. Use pre-sliced onions and sauté them in a hot pan with a bit of butter or oil.

Add a pinch of sugar to help speed up the caramelization process, and use store-bought beef broth to cut down on the preparation time. It’s a shortcut version but still packed with flavor.

6. Add Protein

For a heartier variation, you can add protein to the soup. Thinly sliced roast beef, shredded rotisserie chicken, or even a poached egg can be served in the soup to make it more filling. The tender beef or poultry will absorb the rich, savory broth, creating a comforting meal that’s more substantial.

Best Practices To Store Leftovers

French onion soup with mustard cheese croutes is one of those dishes that tastes even better the next day, once the flavors have had a chance to meld together. However, proper storage is key to ensuring the soup maintains its delicious flavor and texture.

1. Storage Containers

Always store leftover French onion soup in an airtight container to preserve its flavor and prevent it from absorbing odors from other foods in the fridge. For the best results, separate the soup and croutes, as the bread will absorb the broth and become soggy, losing its texture. Store the soup in one container and the croutes in a sealed plastic bag or another container.

2. Refrigeration

Leftover French onion soup can be stored in the refrigerator for up to 3-4 days. Be sure to let the soup cool down to room temperature before transferring it to the fridge. Rapid cooling is essential to avoid any bacterial growth, so if you’re storing it right after cooking, consider dividing it into smaller portions to help it cool quickly.

3. Freezing For Longer Storage

If you want to extend the shelf life of your French onion soup, freezing is a great option. Ladle the soup into freezer-safe containers or zip-lock freezer bags, leaving some room for expansion.

The soup can last for up to 3 months in the freezer. To reheat, simply thaw the soup overnight in the fridge and warm it on the stove over low heat.

4. Reheating

When reheating the soup, do so gently on the stove over low heat, stirring occasionally. If you notice the soup has thickened too much during storage, you can thin it out by adding a splash of broth or water. When it comes to reheating the mustard cheese croutes, it’s best to toast them fresh for the best texture, or you can gently reheat them in the oven for a few minutes.

What Goes Well With French Onion Soup With Mustard Cheese Croutes

Mary Berry’s French onion soup with mustard cheese croutes is a complete meal in itself, but pairing it with complementary sides and drinks can elevate the experience. Here are a few ideas to make your meal even more special:

1. Salads

A light, crisp salad is the perfect contrast to the rich, hearty nature of French onion soup. A simple green salad with arugula, mixed greens, and a tangy vinaigrette provides a refreshing balance. For an added twist, you could also include roasted beets, goat cheese, or candied walnuts to introduce sweetness and texture.

2. Wine Pairings

French onion soup is a rich and savory dish, so pairing it with a wine that has a good balance of acidity is important. A crisp white wine, such as Sauvignon Blanc or Chardonnay, complements the sweetness of the onions and cuts through the richness of the cheese. If you prefer red wine, a light Pinot Noir or a medium-bodied Merlot works well without overwhelming the flavors of the soup.

3. Crusty Bread

While the mustard cheese croutes are delicious, a side of crusty French baguette or rustic sourdough is always a great accompaniment. The bread can be used to mop up any leftover broth, and its crusty texture offers a nice contrast to the soft, melted cheese on the croutes.

4. Roasted Vegetables

A side of roasted vegetables such as carrots, parsnips, or Brussels sprouts would pair wonderfully with French onion soup. The natural sweetness of roasted vegetables complements the soup’s deep flavors, and their crispy texture adds contrast to the softness of the soup.

5. Charcuterie Board

For a more indulgent side, a charcuterie board with a selection of cured meats, pâté, and a variety of cheeses would make an excellent accompaniment. The saltiness of the meats and the richness of the cheese contrast beautifully with the soup’s sweet and savory profile, creating a luxurious and satisfying meal.

Conclusion

Mary Berry’s French Onion Soup with Mustard Cheese Croutes is a perfect blend of deep flavors and textures, with the caramelized onions and savory broth providing a satisfying base and the cheesy croutes bringing a touch of decadence. Whether you stick to the classic recipe or try out some fun variations, the versatility of the dish means it can be adapted to suit your mood or dietary preferences.

It’s an ideal dish for both cozy weeknight dinners and special occasions, and its rich, hearty nature makes it a crowd-pleaser every time. And with the right storage practices and tasty sides, you can enjoy this comforting meal again and again.

FAQs

What Makes Mary Berry’s French Onion Soup Different From Other Versions?

Mary Berry’s French onion soup stands out due to its depth of flavor, which is achieved by slowly caramelizing the onions to develop a rich, sweet base. The addition of mustard cheese croutes provides a unique twist, combining tangy mustard and melted cheese on crispy bread for extra flavor and texture.

What Are The Key Ingredients For Mary Berry’s French Onion Soup With Mustard Cheese Croutes?

The key ingredients include onions, butter, beef stock, white wine, thyme, bay leaves, and a touch of sugar to balance the sweetness of the onions. For the mustard cheese croutes, you’ll need baguette slices, Dijon mustard, gruyère cheese, and occasionally a sprinkle of fresh parsley.

Can I Make Mary Berry’s French Onion Soup Vegetarian?

Yes, you can make the soup vegetarian by substituting the beef stock with vegetable stock. This will maintain the depth of flavor without compromising the overall taste of the soup.

How Long Does It Take To Prepare Mary Berry’s French Onion Soup With Mustard Cheese Croutes?

The total preparation time is around 1 hour and 30 minutes. This includes about 40-45 minutes to caramelize the onions properly and about 15 minutes for assembling and baking the mustard cheese croutes.

What Type Of Cheese Is Best For The Mustard Cheese Croutes?

Gruyère cheese is the traditional choice, as it melts beautifully and adds a nutty, savory flavor that complements the sweetness of the onion soup. You can also use a combination of gruyère and cheddar if you prefer a stronger cheese flavor.

Can I Make The Mustard Cheese Croutes Ahead Of Time?

Yes, you can prepare the mustard cheese croutes in advance. Once assembled, you can store them in an airtight container and bake them just before serving. This ensures the croutes stay crisp and fresh.

How Do I Prevent The Onions From Burning When Caramelizing Them?

To prevent burning, cook the onions on a low to medium heat and stir them regularly. Adding a pinch of salt can also help draw out moisture from the onions, which helps them cook evenly. Be patient-caramelizing onions properly takes time, usually around 30-40 minutes.

Can I Freeze Mary Berry’s French Onion Soup?

Yes, the soup can be frozen without the mustard cheese croutes. Allow the soup to cool completely, then store it in an airtight container or freezer bag for up to 3 months. To serve, reheat the soup and make fresh croutes as desired.

How Do I Make The Soup Thicker Or Thinner?

To thicken the soup, you can cook it for a longer time to reduce the liquid, or add a little cornstarch mixed with water. To make it thinner, simply add more stock or water until you reach your desired consistency.

Can I Make Mary Berry’s French Onion Soup With Other Types Of Bread For The Croutes?

Yes, you can use other types of bread such as sourdough, whole-grain, or even a baguette with a slightly different texture. However, a crusty bread like a baguette is preferred for its ability to hold up well when topped with cheese and mustard, then baked.