French Onion Soup

Ingredients

• 30 ml (2 tablespoons)good-quality olive oil
• 35 g (2½ tablespoons)salted butter
• 907 g (2 pounds), halved and cut into 6 mm (¼-inch) slicesyellow onions
• 227 g (½ pound), halved and cut into 6 mm (¼-inch) slicessweet onion
• 6 sprigsthyme
• 60 ml (¼ cup)brandy
• 240 ml (1 cup)dry vermouth or Sauvignon Blanc
• 12.5 ml (2½ teaspoons)Worcestershire sauce
• 12.5 ml (2½ teaspoons), plus more to tastefish sauce
• 1½ tablespoonsfresh garlic, minced
• 1 largebay leaf
• 5 ml (1 teaspoon), plus more to tastekosher salt
• 2.5 ml (½ teaspoon), plus more to tastefreshly cracked black pepper
• 1.3 litres (5½ cups)homemade or good-quality low-sodium beef stock
• ½ baguette, cut into 1.3 cm (½-inch) slicesbaguette
• to tasteolive oil, for the bread
• 1 large clove, halvedgarlic, for rubbing on the toast
• 100 g (1 cup), freshly shreddedGruyère
• 50 g (½ cup), freshly gratedComté
• to taste, optionalchives, finely chopped

Instructions

1. 1

   Caramelise the onions

   Warm the olive oil and butter in a pot over medium heat. When the butter has melted, add the onions and stir every few minutes. Cook slowly for 1 hour 15 minutes to 1 hour 40 minutes, avoiding rapid browning. If the pot becomes dry, add 1½ teaspoons of water at a time and stir.

2. 2

   Build the fond

   Once the onions are deeply browned and caramelised, raise the heat to medium-high. Cook for 2–3 minutes, allowing a brown glaze, or fond, to form on the bottom of the pot.

3. 3

   Add the garlic

   When the onions and fond are a deep brown, stir in the minced garlic. Cook for 2 minutes, or until fragrant.

4. 4

   Deglaze the pot

   Pour in the brandy and scrape the browned bits from the bottom of the pot. Cook until most of the liquid has evaporated. Add the vermouth or white wine and cook until reduced by about half, approximately 4 minutes.

5. 5

   Simmer the soup

   Stir in the Worcestershire sauce, fish sauce and ½ teaspoon black pepper. Add the thyme sprigs, bay leaf and beef stock. Bring to the boil, then reduce to a simmer. Cover, leaving a small gap, and cook for 40 minutes, stirring occasionally. While it simmers, preheat the oven to 200°C (400°F) and toast the bread.

6. 6

   Toast the baguette

   Arrange the baguette slices on a baking tray and drizzle with olive oil. Bake for 5–8 minutes, until toasted and lightly browned, then remove from the oven and set aside.

7. 7

   Season and grill

   Taste the soup and adjust with more salt and freshly cracked black pepper if needed. Set the oven to the grill setting.

8. 8

   Assemble the bowls

   Rub the cut sides of the fresh garlic over the toasted bread, including the corners. Set oven-safe bowls on a baking tray and ladle in the soup. Top with the garlic toasts and as much Gruyère and Comté as desired. Bake until the cheese has melted completely and started to brown slightly. Finish with chives if using.

What is French onion soup?

French onion soup is a classic French dish built around onions slowly cooked until sweet and deeply browned, then simmered in stock. It is often served with bread and bubbling cheese on top.

This version layers yellow and sweet onions with brandy, vermouth, beef stock and two savoury sauces. Gruyère and Comté melt over garlic-rubbed baguette for a rich, hearty finish.

Nutrition and macros by portion

The nutrition label shows one serving as written: 680 calories, 26g protein, 63g carbs, 35g fat.

The onions and baguette provide most of the carbohydrates, while olive oil, butter and the cheese contribute much of the fat. Beef stock and the two cheeses supply protein, with the stock, salted butter, sauces and cheese also contributing sodium. For a more balanced plate, serve a bowl with a simple green salad.

Why the onions take time

Yellow onions: these provide a savoury base and hold their character through the long cooking.

Sweet onion: it adds another layer of sweetness, but the mix still needs a slow cook to develop its full caramelised flavour. Stir every few minutes and let the colour build gradually.

Developing the pot flavour

Fond: after the onions are deeply browned, a glaze forms on the pot bottom. Let it develop for the stated 2–3 minutes without allowing it to burn.

Deglazing: brandy loosens the browned bits, while the vermouth is reduced by about half. Scraping as you pour helps those concentrated flavours become part of the broth.

Balancing the savoury broth

Sauces: Worcestershire and fish sauce add savoury depth alongside the beef stock. Their saltiness can vary, so taste the finished soup before adding extra salt.

Aromatics: thyme and bay leaf infuse the simmering broth. Remove the sprigs and leaf before ladling if they remain in the pot.

Getting the toast and cheese right

Baguette: a brief bake dries and colours the slices so they can support the soup and toppings. Rub with the halved garlic clove after toasting, as directed.

Cheese: freshly shredded Gruyère and grated Comté melt over the bread. Grill the assembled bowls only until the cheese is melted and beginning to brown.

Timing and serving

The long part is caramelising the onions, which takes 1 hour 15 minutes to 1 hour 40 minutes; the soup then simmers for 40 minutes. Keep the onion stage unhurried, as it provides much of the dish’s flavour.

Serve the soup hot in oven-safe bowls, straight after the cheese has melted. The recipe makes three servings; use bowls that can safely go under the grill.

Recipe notes & tips

• Slice the onions evenly so they cook at a similar pace.
• Stir regularly during the long onion cook, scraping the base if browning develops.
• If the onions begin to dry out, add water 1½ teaspoons at a time rather than letting them catch.
• Reduce the vermouth until about half remains before adding the stock.
• Taste before adding extra salt, since the stock, sauces and cheeses can all be salty.
• Use oven-safe bowls and place them on a baking tray before filling.

Variations

• Use white wine: replace the dry vermouth with Sauvignon Blanc as suggested in the recipe.
• Adjust the cheese: use more or less Gruyère and Comté to suit your preference.
• Add chives: scatter finely chopped chives over the finished bowls for a fresh garnish.
• Choose low-sodium stock: this gives you more control when seasoning the soup.
• Change the bread: use another baguette-style loaf, sliced to the same thickness for toasting.

Common mistakes to avoid

• Rushing the onions: fast browning can leave them uneven; cook slowly for the full stated time.
• Letting the pot dry out: add water 1½ teaspoons at a time and stir when the onions need moisture.
• Burning the fond: let it brown gradually and keep an eye on the pot during the brief medium-high stage.
• Adding salt too early: taste after simmering and adjust carefully because several ingredients are already salty.
• Skipping the bread toast: bake it until lightly browned so it holds up under the soup and cheese.
• Over-grilling the bowls: remove them once the cheese has melted and begun to brown.

How to store

Cool leftover soup promptly and refrigerate in a covered container for up to 3 days. Store the soup separately from the bread and cheese, then reheat the soup until piping hot and assemble with freshly toasted baguette and cheese before grilling.

Frequently asked questions