Onion soup is older than France; the Romans made one, and a richly spiced version appears in a Paris household book from 1393. For most of its life, though, it was regarded as food for the poor, cheap, filling and made from whatever the onion basket held. The bowl the world now knows, gratinée under a lid of bread and molten cheese, belongs to Paris and especially to Les Halles, the vast central food market, where the bistros around the stalls served it through the night to market workers starting their shift and revelers finishing anything but. It has kept its reputation as the cure for a long night ever since.

There is no secret to it beyond patience. The onions must cook slowly, for the best part of an hour, until they collapse into a sweet, dark amber tangle; rushed onions give a thin, harsh soup. After that it is quick work: broth, a little wine, toast and a generous blanket of cheese under a hot broiler. It is the dish for a cold, grey race morning, when the grid is damp, the forecast is uncertain and only the soup can be counted on.

The onion soup

Ingredients

• 4 tablespoons (55 g) unsalted butter
• 1 tablespoon (15 ml) olive oil
• 3 lb (1.4 kg) yellow onions
• 1 teaspoon fine salt
• 1 teaspoon sugar
• 2 tablespoons (15 g) all purpose flour
• 1/2 cup (120 ml) dry white wine
• 6 cups (1.4 liters) beef stock
• 2 sprigs fresh thyme
• 1 bay leaf
• to taste freshly ground black pepper

Method

1. Melt the butter with the oil in the large pot over medium heat. Add all the onions and the salt; the pot will be very full. Stir well, cover with the lid and cook for 10 minutes, stirring twice, so the onions soften and shrink.
2. Take off the lid, turn the heat to medium low and cook for 40 to 50 minutes, stirring every 5 minutes or so and scraping the browned film from the bottom of the pot back into the onions. If the bottom starts to look dark brown or smell scorched, add 2 tablespoons of water and scrape it up. Add the sugar only if the onions are still pale after 30 minutes.
3. Sprinkle the flour over the onions and stir for 2 minutes so it cooks. Pour in the wine and scrape the bottom of the pot hard with the wooden spoon to lift all the browned bits, then let it bubble for 1 minute.
4. Pour in the hot stock a little at a time, stirring, then add the thyme and bay leaf. Bring to a boil, lower the heat and simmer gently, uncovered, for 25 to 30 minutes.
5. Fish out the thyme stems and bay leaf. Taste and add salt and plenty of black pepper. The soup should taste rich and savory with a clear sweetness from the onions.

The cheese crust

Ingredients

• 8 slices of baguette
• 1 garlic clove
• 6 oz (170 g) Comté or Gruyère

Method

1. Heat the oven to 400°F (200°C). Lay the bread slices on the baking sheet and bake for 8 to 10 minutes, turning once, until dry and crisp. Rub one side of each slice lightly with the cut garlic if you like.
2. Set the ovenproof bowls on the baking sheet. Switch the oven to broil on high and move a rack to about 6 inches (15 cm) below the heat. Ladle the hot soup into the bowls, filling them almost to the rim. Float two slices of toast on each, then pile the grated cheese generously over the toast, letting it reach the edges of the bowl.
3. Slide the baking sheet under the broiler and cook for 3 to 6 minutes, watching closely through the oven door, until the cheese is melted, bubbling and browned in patches. Lift out the tray with oven mitts and let the bowls stand for 2 minutes. Warn everyone that the bowls are extremely hot.

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