Classic French Onion Soup With Gruyère Croutons

Name: Classic French Onion Soup With Gruyère Croutons
Prep time: 15 min
Cook time: 75 min
Total time: 90 min
Yield: 4 servings
Cuisine: French
Ingredients: 1kg (about 6 large) yellow or brown onions, thinly sliced; 60g (4 tablespoons) unsalted butter; 2 tablespoons olive oil; 1 teaspoon salt; 1/2 teaspoon black pepper; 2 tablespoons all-purpose flour; 1 cup (240ml) dry white wine; 1.5 litres (6 cups) good quality beef broth; 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried); 1 bay leaf; 1/4 teaspoon freshly grated nutmeg; 1 French baguette, sliced into 2cm thick rounds; 300g Gruyère cheese, grated; 2 tablespoons fresh parsley, chopped (for garnish)

Published: March 10, 2026 | French Cuisine | ⏱ 1h 30min

Classic French onion soup with melted Gruyère cheese crouton

French onion soup is the quintessential comfort dish — a deeply savoury broth crowned with a golden blanket of melted Gruyère cheese. This recipe honours the Parisian bistro tradition while making it achievable in any home kitchen.

The secret to an unforgettable onion soup lies entirely in the caramelisation. Taking the time to cook the onions slowly — for a full 40 minutes — transforms them into a sweet, amber-coloured base that needs very little else to shine. A splash of dry white wine, a good quality beef broth, and a generous grating of nutmeg complete the foundation.

Serve this soup in individual oven-safe bowls topped with crusty bread and bubbling cheese for a show-stopping starter or a hearty main course with a simple green salad on the side.

Why This Recipe Works

The long, slow caramelisation of the onions breaks down their natural sugars and creates an umami-rich base that requires no artificial flavouring. Topping the soup with Gruyère-toasted bread adds texture, richness, and a satisfying finishing touch.

Recipe Info

Prep Time15 min

Cook Time1h 15min

Total Time1h 30min

Servings4

DifficultyEasy

CuisineFrench

Don't rush the onions. Proper caramelisation is the difference between a good soup and an unforgettable one. If the onions start to stick, add a tablespoon of water instead of more butter or oil.
Use a good quality beef broth — it forms the backbone of the soup. Homemade is best, but a good store-bought brand works well too. Avoid bouillon cubes if possible.
Slice the onions uniformly so they cook evenly. A mandoline makes quick work of this.
Use oven-safe bowls that are stable on a baking sheet. Traditional French onion soup bowls have handles, but any oven-safe crock will work.

Variations

Vegetarian French Onion Soup

Replace the beef broth with a high-quality vegetable broth and add 1 tablespoon of soy sauce or tamari for extra umami depth. Proceed with the recipe as written.

Onion and Apple Soup

Add 2 peeled and sliced tart apples (such as Granny Smith) to the onions during the last 15 minutes of caramelisation. The apple adds a subtle sweetness that complements the savoury broth beautifully.

Provençal Onion Soup

Add 2 sprigs of fresh rosemary, a strip of orange zest, and 1/2 teaspoon of herbes de Provence with the broth. Omit the nutmeg and use a mix of Gruyère and Comté cheese.

Serving Suggestions

Serve the soup piping hot with the cheese still bubbling. A simple green salad with a sharp vinaigrette is the perfect counterpoint to the rich, cheesy soup. A glass of dry white wine such as Sauvignon Blanc or a light red like Beaujolais pairs beautifully. For a heartier meal, serve as a starter before a simple roast chicken or grilled steak.

Nutrition Information

Calories	380 kcal
Protein	22g
Fat	18g
Saturated Fat	10g
Carbohydrates	32g
Fiber	3g
Sugar	8g
Sodium	890mg

* Nutritional values are approximate and based on per-serving calculations.

Storage

Store the soup base (without the bread and cheese topping) in an airtight container in the refrigerator for up to 5 days. Reheat on the stovetop and assemble with fresh bread and cheese when ready to serve. The soup also freezes well for up to 3 months — just leave out the bread and cheese before freezing.

Frequently Asked Questions

Yellow or brown onions are the classic choice — they have the perfect balance of sweetness and savoury flavour. Red onions can be used but will give a slightly different colour and milder flavour.

You can caramelise the onions on the stovetop first, then transfer to a slow cooker with the broth and cook on low for 4-6 hours. However, you won't get the same depth of flavour as the stovetop method without the initial caramelisation.

Comté, Emmental, or a mix of mozzarella and Parmesan all work well. Gruyère is traditional for its nutty flavour and excellent melting qualities, but any good melting cheese will do.

Yes! The soup base is actually better the next day as the flavours meld. Cool completely, refrigerate, and reheat gently. Only add the bread and cheese when you're ready to serve.

Rating

★ ★ ★ ★ ★ 4.8 (95 votes)

About the Author

Stephanie Grine

Recipe Developer & Food Enthusiast

I am a passionate home cook who believes that great food brings people together. Every recipe on TodayFoodsMenu is developed, tested, and photographed in my home kitchen — not a professional test...

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