Quick Authentic French Onion Soup

Ingredients

• 10 ml (2 teaspoons)olive oil
• 680 g (1 1/2 lb)onions
• 1/2 teaspoonherbes de Provence
• 480 ml (2 cups)chicken broth
• 60 ml (1/4 cup)white wine
• 2 teaspoonsplain flour
• 3 slicesbaguette
• 6 tablespoonsGruyère cheese
• 360 ml (1 1/2 cups)chicken broth

Instructions

1. 1

   Prepare the onions

   Heat the olive oil in a large pan over a medium heat. Add the onions, cut into thin strips, the herbes de Provence and salt.

2. 2

   Caramelise the onions

   Cook, stirring now and then, until the onions begin to brown. Add a ladleful of broth and let it evaporate before adding more; repeat 3–4 times, until the onions are evenly caramelised.

3. 3

   Add the wine

   Pour in the white wine and simmer until it has evaporated.

4. 4

   Make the croutons

   Cut the baguette slices, drizzle them with oil and fry until golden.

5. 5

   Thicken the soup

   Stir the plain flour into the caramelised onions, making sure there are no lumps. Gradually add chicken broth or water until the soup reaches your preferred thickness, then adjust the salt to taste.

6. 6

   Assemble the bowls

   Put a toasted baguette slice in each ramekin. Ladle the soup over the bread and top with grated Gruyère.

7. 7

   Bake until golden

   Bake at 200°C (400°F) until the cheese has melted and turned golden.

What is French onion soup?

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

This version keeps the process relatively quick by adding broth as the onions brown and finishing the assembled bowls in the oven. Herbes de Provence and white wine add aromatic notes to the chicken broth.

Nutrition and macros by portion

The nutrition label shows one serving as written: 357 calories, 16g protein, 40g carbs, 14g fat.

The baguette and onions provide most of the carbohydrates, while olive oil and Gruyère contribute much of the fat; chicken broth and Gruyère provide protein. Balance the bowl with a green salad or vegetables on the side.

The onions set the flavour

Even slices: Cut the onions into thin, similar-sized strips so they soften and colour at a similar pace.

Steady heat: Cook over medium heat and stir occasionally. Adding broth as the pan starts to brown helps loosen the browned bits while the onions continue to caramelise.

Build a smooth broth

Wine first: Let the wine simmer until it evaporates before moving on, so its flavour becomes part of the onion base rather than diluting the soup.

Flour carefully: Stir the flour into the onions thoroughly before adding broth. Add the liquid gradually and stir as you go to help prevent lumps and control the thickness.

Toast the baguette

Golden bread: Fry the oiled baguette slices until golden before placing them in the ramekins. Toasting gives the bread a firmer surface to sit beneath the soup.

Serve promptly: Once the soup is poured over the bread, the slices will soften. Add the cheese and bake straight away for a bubbling, browned finish.

Check the final texture

Caramelised onions: Look for onions that are evenly browned and soft, rather than pale or crisp. Stirring and adding broth in small rounds helps them cook without scorching.

Melted topping: The bowls are ready when the Gruyère has melted and browned. Keep an eye on them towards the end, as the cheese can colour quickly.

Plan the timing

Onion cooking: Allow time for the onions to colour gradually; this is the step that gives the soup its characteristic savoury-sweet base. The recipe takes about 50 minutes in total.

Final bake: Prepare the bread and bowls while the soup comes together, then bake just before serving so the topping is hot and the bread has not had time to go completely soft.

What to serve with it

As a starter: Serve a smaller bowl before a simple main course, as the bread and cheese make the soup substantial.

As a light meal: Pair a bowl with a green salad or steamed vegetables for a fresh contrast to the rich, savoury topping.

Recipe notes & tips

• Slice the onions evenly so they cook at much the same rate.
• Stir the onions from time to time and lower the heat if they begin to catch.
• Add broth a ladleful at a time during caramelising, letting each addition evaporate.
• Grate the Gruyère finely so it melts evenly over the bowls.
• Place the ramekins on a baking tray to make them easier to move in and out of the oven.

Variations

• Use vegetable broth: Swap the chicken broth for vegetable broth for a meat-free version.
• Try another cheese: Use Comté or Emmental in place of Gruyère for a different melted topping.
• Add fresh thyme: Stir in a little thyme with the herbs for a more pronounced herbal note.
• Use red wine: Replace the white wine with red wine for a deeper flavour.
• Make extra croutons: Toast additional baguette slices separately and serve them alongside the bowls.

Common mistakes to avoid

• Rushing the onions: They may brown unevenly; cook over medium heat and give them time to soften.
• Letting the pan scorch: Stir and add a ladleful of broth when browned bits build up on the base.
• Adding flour in lumps: Stir it thoroughly into the onions before pouring in the broth.
• Pouring in all the broth at once: Add it gradually so you can judge the soup's thickness.
• Baking too long: Remove the bowls once the cheese is melted and golden so the bread does not become overly soft.

How to store

Store leftover soup and bread separately in covered containers in the fridge for up to 3 days. Reheat the soup in a saucepan until hot, then assemble with fresh or separately toasted bread and cheese and bake until melted.

Frequently asked questions