French onion soup
A classic French onion soup made with caramelised onions, rich stock, and a splash of wine, topped with golden, cheesy mustard croûtes. Comforting, hearty, and perfect for cozy evenings.
Updated : 05 November, 2025
Easy
About 20 min.
Ingredients
50 grams
Butter
1 tablespoon
Olive oil
6
Onion
1.5 tablespoon
Sugar
200 milliliters
White wine
2 liter
Meat broth
3
Laurel leaf
1 stalk
Fresh rosemary
to taste
Salt
to taste
Ground black pepper
0.5
Baguette
as needed
Dijon mustard
25 grams
Hard cheese
Table
Table of volume measurements:
- teaspoon - 5 ml
- dessert spoon - 10 ml
- tablespoon - 20 ml
- glass - 200 ml
Preparation
Step 1
Melt the butter and oil together in a deep saucepan. Add the thinly sliced onions and fry over high heat for a few minutes until it begins to soften. Cover the pan, reduce the heat, and simmer gently for about 10 minutes.
Step 2
Remove the lid, then sprinkle in the sugar along with a little salt and pepper. Fry for a few more minutes until the onions start to turn golden. Cover again and continue to simmer for at least 15 minutes, or until the onions are tender, golden-brown, and fully caramelised.
Step 3
Pour in the wine and boil for a few minutes to reduce slightly. Add the stock and herbs, then cook for another 8-10 minutes to blend the flavours.
Step 4
To make the croûtes, slice the baguette and toast one side under the grill. Spread the untoasted side with mustard, sprinkle with grated cheese, and grill until the cheese is just melted and bubbling.
Step 5
Remove the herbs from the soup, check the seasoning, and adjust if needed. Ladle the hot soup into bowls and top each serving with a cheesy croûte. Serve immediately.