Soupe à l'oignon gratinée

Name: Soupe à l'oignon gratinée
Prep time: 15 min
Cook time: 80 min
Total time: 95 min
Yield: 4
Cuisine: France
Ingredients: 1.2 kg onions (about 6 large), thinly sliced into half-moons; 60 g unsalted butter; 1 tbsp neutral oil; 1 tsp caster sugar (helps caramelisation); 150 ml dry white wine or dry vermouth; 1 litre good beef stock (or rich vegetable stock); 2 sprigs fresh thyme; 1 bay leaf; 1 tbsp plain flour (optional, for a slightly thicker soup); 2 tbsp cognac or brandy (optional); 1 tsp salt; 0.5 tsp black pepper; 8 thick slices baguette, toasted until completely dry and crisp; 200 g Gruyère cheese, coarsely grated (Comté also excellent)

Paris's great restorative: onions caramelised for an hour until dark and sweet, simmered in wine and beef stock, ladled over croutons, and finished under the grill with a volcanic gratin of Gruyère: the definitive onion dish

Origin: France

From the journey of Onion.

Soupe à l'oignon gratinée is the most celebrated onion preparation in the world: a soup built on one foundational act: the caramelisation of onions over low heat for 45 minutes to an hour until they collapse from sharp and pungent to something sweet, dark amber, and deeply complex. French culinary history connects the dish to Paris's Les Halles market, where overnight workers, butchers, fishmongers, florists arriving for the pre-dawn markets, fortified themselves at small restaurants with this restorative soup before their work began. The dish was later codified as a hangover cure and a late-night fortifier, served in the brasseries around Les Halles into the small hours. The gratinée: the thick crust of melted Gruyère cheese that forms a golden, bubbly lid over the crouton-topped soup, distinguishes the Parisian version from simpler provincial onion soups. When the cheese is correctly crusted and pulls into long threads as the spoon breaks through, it is one of the great sensory experiences of French cooking.

Ingredients

Onions

1.2 kg onions (about 6 large), thinly sliced into half-moons

Fat

60 g unsalted butter
1 tbsp neutral oil

Seasoning

1 tsp caster sugar (helps caramelisation)
1 tsp salt
0.5 tsp black pepper

Deglazing

150 ml dry white wine or dry vermouth

Liquid

1 litre good beef stock (or rich vegetable stock)

Herbs

2 sprigs fresh thyme
1 bay leaf

Thickener

1 tbsp plain flour (optional, for a slightly thicker soup)

Enrichment

2 tbsp cognac or brandy (optional)

Croutons

8 thick slices baguette, toasted until completely dry and crisp

Gratin

200 g Gruyère cheese, coarsely grated (Comté also excellent)

Method

Melt the butter with the oil in a large, heavy pot over medium heat. Add all the onions and the sugar. Stir to coat. Cook over medium-low heat for 45–55 minutes, stirring every 5 minutes, until the onions are dark amber, deeply sweet, and significantly reduced in volume.
If using flour: sprinkle over the onions and stir for 2 minutes. This gives a slightly thicker soup; optional in the classical version.
Add the cognac if using. Increase heat to medium-high. Add the white wine and scrape up any browned bits from the bottom of the pot. Cook for 3 minutes until the wine is mostly evaporated.
Add the stock, thyme, and bay leaf. Bring to a boil. Reduce to a gentle simmer. Cook uncovered for 20 minutes. Season with salt and pepper. Remove the thyme and bay.
Preheat the grill to high. Ladle the soup into oven-proof bowls. Place 2 croutons on top of each bowl. Pile the grated Gruyère generously over the croutons; be very generous. Place the bowls on a baking sheet under the hot grill for 3–5 minutes until the cheese is bubbling, golden, and beginning to char at the edges.
Carry the bowls carefully to the table; they are extremely hot. Serve immediately, reminding diners to let the cheese settle for 30 seconds before eating.

Notes

The overnight workers' soup tradition at Les Halles, Paris's great central market, demolished in 1971, gave soupe à l'oignon its reputation as restorative, sustaining, working-class food. The brasseries around Les Halles were among the most vital in Paris: open all night, serving workers from 2 AM onwards with soup, steak, and wine. The dish is now served in every Parisian bistro and brasserie as a national emblem. Good beef stock is non-negotiable; it provides the mineral depth that balances the onion sweetness. The best versions are made with a stock that has itself been produced from roasted bones, giving a dark, gelatinous richness that commercial stock cannot replicate.

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Journey Point Map Key

Ingredient originTrade or transit route

Became a culinary stapleColonial / trade control