Soupe à l'oignon gratinée
Also: French onion soup, Gratinéed onion soup
A French soup of deeply caramelised onions in beef broth, topped with a bread crouton and melted Gruyère browned under a grill.
Identity criteria
- 1Onions cooked low and slow until deeply caramelised — the flavor foundation
- 2A savory broth, classically beef-based, deglazed with wine
- 3A toasted bread crouton floated on the surface
- 4A blanket of grated Gruyère (or Comté) melted and browned (gratinée) on top
- 5Served bubbling hot in an oven-proof bowl
Components
OnionsessentialSlowly caramelised; the soul of the dish
ButteressentialFor caramelising the onions
White wineoptionalTo deglaze; brandy/sherry sometimes added
Beef brothessentialTraditional base; brings savory depth
Salt, pepper, thyme, bayessential
Toasted bread crouton (baguette)essential
Gruyère cheeseessentialMelted and browned on top
Technique
- Slow caramelisation of onions
- Develops the sweet, brown, deep flavor that is the entire identity of the soup
- Deglazing the fond
- Lifts the caramelised sugars into the broth for richness
- Gratinéeing under the grill
- The browned, bubbling cheese-and-bread crust is what makes it gratinée rather than plain onion soup
Form & serving
- Served
- In an individual oven-proof crock, cheese crust on top
- Temperature
- Very hot, bubbling
- Portion
- Starter bowl
- Pairs with
- Dry white wine · Green salad · More crusty bread
Character
Flavour
Texture
Silky onion broth under a chewy crouton and stretchy browned cheese
Eaten
A classic French bistro starter and cold-weather comfort dish, famously eaten late at night in old Paris.
When
autumn · winter
Variations & related
Regional variations
- Les Halles style · Paris
The classic bistro version associated with the old central market
- Comté version · Franche-Comté / Jura
Uses local Comté in place of Gruyère
Related dishes
- ancestor Peasant onion soup
Simple onion-and-broth soups predate the gratinéed refinement
- pairs-with Baguette
The bread that becomes the crouton
Substitutions
Beef broth → Vegetable brothadmissible
Acceptable vegetarian adaptation, though less traditionally rich
Gruyère → Comté or Emmentaladmissible
Acceptable Alpine cheese swaps
Caramelised onions → Lightly sautéed onionsinadmissible
Breaks the dish — without deep caramelisation it lacks its defining sweet depth
Gratinéed cheese crust → No cheese topinadmissible
Breaks the gratinée form — it becomes plain onion soup
Common mistakes
- Rushing the onions so they don't truly caramelise, leaving the soup thin and harsh
- Using watery or weak broth that can't support the onions
- Skipping the gratinée step that defines the dish
- Letting the bread dissolve into mush instead of holding the cheese crust
Provenance
A French dish with roots in humble onion soups, refined into the gratinéed bistro classic associated with Paris and Les Halles; firmly French.
Claimed by: France
References
- 1.French classical and bistro culinary references
Confidence: high