The JQ List may earn a commission when you buy through links in this article.

For more than a century, French onion soup was what Paris ate when the night was nearly over. Its spiritual home was Les Halles, the vast central market Émile Zola called the belly of Paris, where porters, butchers and late-night revelers met in the small hours over steaming bowls of gratinée.

Onion soup itself is ancient and humble, but the Paris version, with its slab of toasted bread and cap of melted cheese, became a restorative for the whole city. The market moved out to Rungis in 1969, yet the soup never left the neighborhood. Brasseries around the old market site still serve it late, and it remains the most comforting thing you can order in Paris on a cold night.

Where to have it in Paris

Walk the streets around Les Halles and Saint-Eustache, then settle into a brasserie for a bowl. Our guide to Paris covers the neighborhoods worth staying in, and for a grander base, read our stay at the Four Seasons George V.

Patience is the only technique

The flavor comes from cooking the onions slowly until they are deep brown, which takes at least an hour. Do not rush it with high heat; they will scorch before they sweeten. Use yellow onions, a good beef stock and real Gruyère or Comté.

Ingredients

Serves 4.

• 3 lb (1.4 kg) yellow onions, thinly sliced
• 4 tbsp (55 g) unsalted butter
• 1 tbsp olive oil
• 1 tsp sugar
• 1 tsp fine salt
• 2 tbsp all-purpose flour
• 1 cup (240 ml) dry white wine
• 6 cups (1.4 liters) rich beef stock
• 2 sprigs thyme and 1 bay leaf
• 1 tbsp Cognac (optional)
• 8 slices baguette, toasted
• 2 cups (200 g) grated Gruyère or Comté

Method

1. Soften the onions. Melt the butter with the oil in a heavy pot. Add the onions, cover and cook over medium-low heat for 15 minutes, until soft.
2. Caramelize. Uncover, add the sugar and salt, and cook for 45 to 60 minutes, stirring often and scraping the bottom, until the onions are a deep mahogany brown.
3. Build the soup. Stir in the flour for 2 minutes, then add the wine and scrape up every browned bit. Add the stock, thyme and bay, and simmer for 30 minutes. Season, and add the Cognac if using.
4. Gratinée. Heat the broiler. Ladle the soup into ovenproof bowls, float two slices of toast on each and cover generously with cheese.
5. Broil. Broil for 3 to 5 minutes, until the cheese is bubbling and browned at the edges. Serve at once.

How to serve it

Straight from the broiler, on a plate to catch the drips, with a green salad to follow. Warn your guests: the bowls are hot.

What to pour

A glass of the same dry white you cooked with, or a light red such as a Beaujolais-Villages. In Paris, some still finish with a small Cognac.

Make a menu of it

Make it the first course before our slow cooker coq au vin or red wine braised short ribs, and end with a tarte tatin. Discover more seasonal cooking At the Table.

Photo: jeffreyw, Wikimedia Commons, CC BY 2.0