Mary Berry French Onion Soup Recipe

Rich caramelized onions and melted Gruyère cheese elevate this Mary Berry French onion soup to a sophisticated favorite you’ll always want at the heart of your winter dinner table. It’s delicious with a crusty baguette, a glass of full-bodied red wine, extra cracked black pepper, a side of fresh green salad; in fact most things.

Mary Berry French Onion Soup Recipe Ingredients

• 45 g (1 1/2 oz) butter
• 1 tablespoon sunflower oil
• 1 kg (2 lb) large white onions, thinly sliced
• 2 teaspoons caster sugar
• 30 g (1 oz) plain flour
• 1.8 litres (3 pints) vegetable, chicken, or beef stock
• Salt and freshly ground black pepper
• 8 Gruyère croûtes (slices of toasted baguette topped with melted Gruyère cheese)

How To Make Mary Berry French Onion Soup Recipe

1. Caramelize the onions: Start by melting the butter with the sunflower oil in a large, heavy-based saucepan over medium heat. Add the thinly sliced onions and cook for a few minutes until they begin to soften. Stir in the caster sugar and reduce the heat to low. Continue cooking, stirring occasionally, for about 20 minutes or until the onions have turned a beautiful, deep golden brown. This slow caramelization is the secret to the soup’s rich, sweet flavor.
2. Develop the base: Once the onions are perfectly caramelized, sprinkle the plain flour into the pan. Stir constantly for 1 to 2 minutes. This brief cooking period ensures the flour loses its raw taste and will act as a stabilizer for the soup, giving the broth a subtle body.
3. Simmer the broth: Gradually pour in your choice of stock—beef stock provides the most traditional deep color, while chicken or vegetable stock offers a lighter finish. Stir well as you add the liquid to prevent lumps. Bring the mixture to a boil, then season with salt and black pepper. Cover the pan and let it simmer gently for 35 minutes, stirring occasionally.
4. Final Seasoning: After the simmering time is up, taste the soup. Adjust the salt and pepper if necessary. The onions should be meltingly tender and the broth should be deeply infused with their sweet, savory essence.
5. Serve with croûtes: Ladle the steaming soup into warmed bowls. Place one golden Gruyère croûte on top of each bowl so it floats on the surface. Serve immediately while the cheese is bubbly and the bread is starting to soak up the rich broth.

Recipe Tips

• Patience with Onions: Don’t be tempted to rush the caramelization by turning up the heat. High heat will burn the onions and make them bitter; low and slow is the only way to achieve that signature sweetness.
• Stock Selection: For a truly classic “Parisian” experience, use a high-quality beef stock. If you want a vegetarian version, a robust vegetable stock with a splash of soy sauce can help mimic the deep umami flavor.
• The Flour Step: Don’t skip the flour! It prevents the onions from all sinking to the bottom and gives the broth a silky, professional mouthfeel.
• The Croûtes: For the best results, use a sturdy French stick (baguette). Toast the bread first, pile on the Gruyère, and grill until the cheese is spotted with brown before placing them in the soup.

What To Serve With Mary Berry French Onion Soup Recipe?

This Mary Berry French Onion Soup Recipe is a rich, comforting meal that needs a fresh or crisp pairing! An Extra Crusty Baguette is the quintessential choice for mopping up the savory broth. For a more balanced dinner, a Crisp Green Salad with a sharp mustard vinaigrette adds a lovely acidic contrast to the sweet onions! A side of Roasted Asparagus or a glass of Chilled White Wine pairs wonderfully with the nutty Gruyère and onion notes.

How To Store Mary Berry French Onion Soup Recipe

• Refrigerate: Store the soup (without the croûtes) in an airtight container for up to 3 days. The flavor often improves after a night in the fridge.
• Reheat: Warm gently on the stovetop over medium-low heat. Prepare fresh croûtes just before serving to ensure the bread is crunchy.
• Freezing: The soup base freezes exceptionally well for up to 3 months. Thaw in the fridge overnight before reheating and finishing with the cheese-topped bread.

Mary Berry French Onion Soup Recipe Nutrition Facts

• Calories: 353 kcal (per serving)
• Total Fat: 16 g
• Saturated Fat: 9 g
• Cholesterol: 40 mg
• Sodium: 920 mg
• Total Carbohydrates: 34 g
• Protein: 14 g
• Fiber: 4 g

Nutrition information is based on Mary Berry’s estimate of 353 calories per serving.

FAQs

Mary Berry French Onion Soup Recipe

Recipe by Emily HartwoodCourse: SoupsCuisine: French InspiredDifficulty: Easy

Servings

8

servings

Prep time

15

minutes

Cooking time

1

hour 

Calories

353

kcal

A classic, deep-flavored soup featuring slowly caramelized onions in a rich broth, topped with toasted Gruyère cheese croûtes.

Ingredients

• 1 kg large white onions

• 1.8 L stock (beef, chicken, or veg)

• 45g butter & 1 tbsp sunflower oil

• 30g plain flour

• 2 tsp caster sugar

• 8 Gruyère croûtes

Directions

• Melt butter and oil; cook onions until soft.
• Add sugar and cook on low for 20 minutes until golden brown.
• Stir in flour and cook for 1-2 minutes.
• Gradually whisk in the stock and bring to a boil.
• Cover and simmer for 35 minutes, stirring occasionally.
• Serve hot topped with a toasted Gruyère croûte.

Notes

• The sugar helps the onions achieve a deep caramel color without burning.
• Use a heavy-bottomed pan to ensure even heat distribution.
• This recipe is a perfect starter for a dinner party as the base can be made ahead.