Soupe à l'Oignon
A rich, deeply caramelized onion soup topped with toasted bread and melted Gruyère cheese.
Origin & history
Onion soup has been a staple of French cuisine since Roman times, but the modern version with a gratinéed cheese topping became popular in Parisian markets during the 18th and 19th centuries, often served to workers as a restorative meal.
Ingredients
Quantities recalculate automatically.
Soup
Topping
The method
Step by step
- 01
Caramelize Onions
45 minMelt butter in a heavy-bottomed pot. Add onions and cook over low heat, stirring frequently, until they are deep golden brown and jammy. This is the most important step for flavor.
Patience is key; do not rush the caramelization.
- 02
Simmer
35 minAdd flour to the onions and cook for 2 minutes. Deglaze with a splash of wine (optional) or stock. Add the remaining stock and simmer for 30 minutes.
Skim any foam from the surface.
- 03
Gratiné
5 minLadle soup into oven-safe bowls. Top with toasted baguette slices and a generous amount of Gruyère. Broil until the cheese is bubbling and browned.
Place bowls on a baking sheet to catch drips.
Chef tips
- — Use a mix of onion types for depth.
- — Don't skip the flour; it thickens the soup slightly.
Common mistakes
- — Burning the onions.
- — Using weak, watery stock.
Substitutions
- Beef stock → Vegetable stockUse a dark, rich vegetable stock for a vegetarian version.
Storage & serving
Soup base keeps well in the fridge for 3 days; add bread and cheese just before serving.
Serve piping hot.
Food safety
Ensure the soup is boiling before adding the cheese. Use caution with hot oven-safe bowls.
From the community
Reviews
0 ratings
No published reviews yet. If you cook this dish, yours will be the first.
Cooked this dish?
Sign in to rate the recipe, leave notes for other cooks and keep it in your cookbook.