Classic French Onion Soup

Ingredients

• 42 g (3 tablespoons)unsalted butter
• 4 largeyellow onions, thinly sliced
• 3 clovesgarlic, minced
• 3 sprigsfresh thyme
• 1bay leaf
• 1.25 ml (1/4 teaspoon)black pepper
• 2.5 ml (1/2 teaspoon)kosher salt
• 120 ml (1/2 cup)dry white wine
• 80 ml (1/3 cup)red wine
• 950 ml (4 cups)beef stock
• 4 slicesthick crusty bread
• 200 g (2 cups)Gruyère, grated

Instructions

1. 1

   Caramelise onions

   Melt the butter in a large pot or Dutch oven over medium heat. Add the onions and sauté for approximately 20–30 minutes, until soft, golden brown and caramelised.

2. 2

   Add aromatics

   Stir in the garlic, thyme sprigs, bay leaf, salt and pepper. Cook for 5 minutes.

3. 3

   Simmer soup

   Add both wines and bring to the boil. Reduce the heat, remove the thyme sprigs and bay leaf, then add the beef stock. Bring to a simmer and cook for another 10 minutes. Taste and adjust the salt and pepper if necessary.

4. 4

   Broil with cheese

   Preheat the broiler. Set oven-safe ramekins or cast-iron cocottes on a sheet pan. Ladle in the soup, then top each portion with a slice of bread and grated cheese. Broil on high for about 2–3 minutes, until the cheese has melted.

5. 5

   Serve with toast

   Alternatively, broil the bread slices separately on a sheet pan for 2–3 minutes, until crisp, and serve them with the soup.

What is French onion soup?

French onion soup is a classic French dish built around onions cooked until deeply golden, then simmered in stock and served with bread and melted cheese. Its appeal comes from the contrast between savoury broth, sweet onions and a crisp, cheesy topping.

This version uses both white and red wine for depth, while thyme and bay leaf lend herbal notes. Gruyère melts over thick slices of crusty bread for a hearty finish.

Nutrition and macros by portion

The nutrition label shows one serving as written: 480 calories, 23g protein, 27g carbs, 27g fat.

The onions and bread provide most of the carbohydrates, while butter and Gruyère contribute much of the fat. Beef stock and Gruyère supply protein, with the stock also contributing sodium. Pair a bowl with a simple green salad or extra vegetables for a more balanced plate.

The importance of slow onions

Onions: Slice them thinly so they soften evenly, and give them the full 20–30 minutes over medium heat. They should turn golden and tender before you move on.

Butter: It coats the onions as they cook and contributes to the soup’s rounded flavour. Stir occasionally so the onions cook evenly.

Wine and aromatics

Wine: Adding both wines and bringing them to the boil is part of the method before the stock goes in. Once the heat is reduced, remove the thyme sprigs and bay leaf.

Seasoning: Salt and pepper are added with the aromatics, then checked again after simmering. Taste before serving and adjust only if needed.

Building the topping

Bread: Thick, crusty slices give the topping enough substance to sit over the soup. The recipe offers two approaches: broil the bread on the soup, or crisp it separately and serve it alongside.

Cheese: Spread the grated Gruyère over the bread so it melts under the broiler. Keep a close eye on it during the 2–3-minute cook.

Timing and texture cues

Onions: The longest stage is the initial sauté, which takes approximately 20–30 minutes. Look for soft onions with a golden-brown colour rather than stopping as soon as they begin to soften.

Soup: After the wine comes to the boil and the herbs are removed, simmer the stock mixture for another 10 minutes. The finished soup should be hot, with tender onions throughout.

Serving the soup

For the broiled version, use oven-safe ramekins or cast-iron cocottes arranged on a sheet pan. This makes it easier to put the filled dishes under the broiler.

Serve the soup as soon as the cheese has melted. If you choose the separate-toast option, bring the crisp bread to the table alongside the bowls.

Recipe notes & tips

• Slice the onions thinly so they soften at a similar rate.
• Allow the onions the full 20–30 minutes to become soft and golden.
• Remove the thyme sprigs and bay leaf before adding the stock.
• Use oven-safe dishes for the broiler method.
• Watch the cheese closely, as it only needs about 2–3 minutes to melt.

Variations

• Use separate toast: Broil the bread on a sheet pan for 2–3 minutes and serve it alongside the soup.
• Choose another melting cheese: Replace Gruyère with a cheese that melts well.
• Adjust the herbs: Use a different mix of fresh herbs in place of the thyme.
• Make it vegetarian: Use vegetable stock instead of beef stock.
• Vary the bread: Use another thick slice of crusty bread for each serving.

Common mistakes to avoid

• Rushing the onions: They may not become soft and golden; allow approximately 20–30 minutes.
• Skipping the tasting: Check the seasoning after the stock simmers and adjust salt and pepper if needed.
• Leaving herbs in the pot: Remove the thyme sprigs and bay leaf before adding the stock.
• Using non-oven-safe dishes: Choose ramekins or cocottes suitable for the broiler.
• Walking away from the broiler: Check after 2 minutes so the cheese melts without overcooking.

How to store

Refrigerate leftover soup in a covered container for up to 3 days. Store the bread and cheese topping separately where possible, then reheat the soup on the hob until hot and add the topping just before serving.

Frequently asked questions