French Onion Soup

Ingredients

• 6 jumbo (about 1.36 kg or 2.4–2.8 litres total)yellow onions, thinly sliced from top to bottom
• 60 ml (4 tbsp), dividedolive oil
• 30 g (2 tbsp)salted butter
• 4 g (1 tsp)granulated sugar
• 5 g (1 tsp)salt
• 3 clovesgarlic, minced
• 2.37 litres (10 cups)beef stock
• 120 ml (½ cup)dry red or white wine
• 2 mediumbay leaves
• 30 ml (2 tbsp), optionalbrandy or sherry
• 1 tbspfresh thyme leaves
• 2.5 g (½ tsp)black pepper
• 8 slices, 2.5 cm (1 inch) thick, cut on the diagonalFrench bread or baguette
• 22.5 ml (1½ tbsp)olive oil
• About 200 g (2 cups)Gruyère or Swiss cheese, shredded
• About 25 g (¼ cup)Parmesan cheese, grated

Instructions

1. 1

   Heat the oil

   In a heavy-based 5.7-litre (6-quart) casserole or pot, warm 45 ml (3 tbsp) of the olive oil over a medium heat. Add the sliced onions and stir to coat.

2. 2

   Soften onions

   Cook uncovered, stirring often, for about 15–20 minutes, until the onions have softened.

3. 3

   Start browning

   Raise the heat to medium-high. Add the remaining 15 ml (1 tbsp) olive oil and the butter, then cook, stirring often, for about 10–15 minutes more, until the onions begin to brown.

4. 4

   Caramelise onions

   Stir in the sugar and salt and continue cooking for about 10–15 minutes, until the onions are a deep golden brown. Add the garlic and cook for 1 minute, or until fragrant.

5. 5

   Deglaze the pot

   Pour in the wine and scrape the browned bits from the bottom and sides of the pot.

6. 6

   Simmer the soup

   Add the beef stock, bay leaves, thyme and pepper. Bring to a simmer, cover and cook over a medium-low heat for about 30 minutes.

7. 7

   Season the soup

   After 30 minutes, uncover and adjust the salt and black pepper to taste. Remove the bay leaves and stir in the brandy or sherry, if using.

8. 8

   Prepare the oven

   Just before serving, preheat the oven to 230°C (450°F). Line a large baking tray with baking parchment and move an oven rack to the upper third of the oven.

9. 9

   Oil the bread

   Brush both sides of the French bread lightly with olive oil.

10. 10

    Toast one side

    Arrange the bread on the tray and bake for about 5 minutes, until lightly browned. Remove it from the oven, turn the slices over, then top with Gruyère and a sprinkling of grated Parmesan.

11. 11

    Melt the cheese

    Return the tray to the oven for a few minutes, just until the cheese is bubbly and lightly golden.

12. 12

    Serve the soup

    Ladle the soup into bowls or oven-safe soup crocks. Top each portion with one piece of cheese bread and garnish with fresh thyme or chives.

13. 13

    Serve immediately

    Serve the soup straight away.

What is French onion soup?

French onion soup is a slow-cooked onion soup traditionally associated with France, usually served with bread and melted cheese. This version builds savoury depth with beef stock, wine and herbs, then finishes each bowl with a separate cheese toast.

The success of the soup rests on taking the onions through several stages of cooking rather than rushing them. Their gradual browning brings sweetness and colour to the broth.

Nutrition and macros by portion

The nutrition label shows one serving as written: 504 calories, 23g protein, 51g carbs, 22g fat.

The bread provides much of the carbohydrate, while olive oil, butter and cheese contribute most of the fat. Beef stock and the cheese supply protein, with the onions adding sweetness and some carbohydrate. Pair a bowl with a generous green salad or other vegetables for a more balanced plate.

Let the onions take their time

Softening: The first cooking stage gives the onions time to lose moisture and become tender. Stir frequently so the slices cook evenly without catching.

Browning: Butter, oil, sugar and salt help the onions develop colour and flavour. Keep stirring as they deepen to a rich golden brown; the colour in the pot will carry into the soup.

Build flavour in the pot

Wine: Pour it in after the garlic and scrape the base of the pot to loosen the browned residue. This step puts those concentrated flavours into the broth.

Stock and herbs: Beef stock gives the soup its savoury backbone, while bay leaves, thyme and pepper season the simmer. Remove the bay leaves before serving, and add the optional brandy or sherry after cooking.

Get the cheese toast right

Bread: Slices cut about 2.5 cm thick can hold the cheese without disappearing into the soup too quickly. Brushing both sides with oil helps them toast evenly.

Cheese: Gruyère or Swiss melts over the toast, while Parmesan adds a savoury finish. Watch closely during the final few minutes: the aim is bubbly, lightly golden cheese.

Use colour as your cue

The onions should become soft first, then noticeably browned, and finally a deep golden colour after the sugar and salt go in. If they are still pale at the end of the stated cooking stages, keep cooking and stirring until they reach that colour.

The broth only needs a gentle simmer for its 30-minute covered cook. A vigorous boil is unnecessary; lower the heat if it starts bubbling hard.

Plan the timing

Most of the 90-minute total time goes towards softening and browning the onions, followed by the soup's 30-minute simmer. Keep the cheese toast until just before serving so it is crisp at the edges and freshly melted.

The soup and toast are prepared separately here, so you do not need oven-safe bowls. Add one cheese toast to each bowl at the table.

What to serve alongside

A simple green salad or lightly dressed leaves provide a fresh contrast to the rich broth and cheese toast. Serve the soup as a starter or make it the main dish with the bread already included.

For a larger meal, pair it with a plain salad rather than another rich side. The soup is filling, so let the toppings and accompanying portions suit the occasion.

Recipe notes & tips

• Slice the onions evenly so they soften and brown at a similar rate.
• Stir often during browning, especially once the onions start to colour.
• Scrape the base of the pot thoroughly when you add the wine.
• Taste the broth after removing the bay leaves and adjust the seasoning before serving.
• Bake the cheese toast just before serving to keep it crisp.
• Keep an eye on the toast under the upper oven rack so the cheese does not over-brown.

Variations

• Use white wine: Choose a dry white wine instead of red for the deglazing step.
• Skip the spirits: Leave out the optional brandy or sherry for a simpler broth.
• Choose Swiss: Use Swiss cheese in place of Gruyère for the toast.
• Add chives: Finish each bowl with chopped chives instead of fresh thyme.
• Make it vegetarian: Use vegetable stock in place of beef stock, noting that the flavour will differ.

Common mistakes to avoid

• Rushing the onions: They will lack the deep colour and flavour; cook until they are richly golden, stirring often.
• Letting the onions catch: Lower the heat slightly and stir more frequently if browned bits start turning very dark.
• Leaving browned bits behind: Scrape the bottom and sides of the pot as you add the wine.
• Boiling the broth hard: Reduce the heat to maintain a gentle simmer for the covered cooking time.
• Over-toasting the bread: Check after about 5 minutes and remove it once lightly browned.
• Over-browning the cheese: Watch the final minutes in the oven and take the tray out once bubbly and lightly golden.

How to store

Store leftover soup without the cheese toast in a covered container in the fridge for up to 3 days. Reheat gently in a saucepan until steaming, and make fresh cheese toast just before serving; stored toast will soften.

Frequently asked questions