Chef’s note
Deeply caramelized onions in a rich beef broth, finished with sherry and parmesan stirred right into the soup, then ladled under a cap of toasted baguette and broiled gruyère. Sweet onions, salty broth, melted cheese — there’s a reason this is the soup that stops conversations.
French Onion Soup
Serves
6 to 8
Prep time
15 minutes
Cook time
1 hour
Total time
1 hour 15 minutes
Ingredients
Soup
- 4 tablespoons unsalted butter
- 1 teaspoon granulated sugar
- 3 pounds yellow onions, thinly sliced (about 12 cups raw)
- 8 cups (2 quarts) hot beef broth
- ¼ cup beef base (or 4 bouillon cubes — adjust salt accordingly)
- 1 tablespoon Worcestershire sauce
- 1 tablespoon Kitchen Bouquet (optional, for color)
- ¼ teaspoon white pepper
- ½ cup grated parmesan
- ½ cup dry sherry
To finish (per bowl)
- 2 thick slices toasted baguette
- ¾ cup shredded gruyère (or a mix of gruyère and Swiss)
Instructions
- Caramelize the onions. In a wide heavy-bottomed pot or Dutch oven, melt the butter with the sugar over medium-low heat. Add the onions and toss to coat. Cook 35 to 45 minutes, stirring occasionally, until deeply golden brown — not just translucent. Be patient: this is the whole soup.
- Build the broth. Meanwhile, in a separate stockpot, combine the hot broth, beef base, Worcestershire, Kitchen Bouquet (if using) and white pepper. Bring to a simmer.
- Stir in the parmesan one big spoonful at a time, whisking until melted and smooth.
- Combine. Add the caramelized onions and the sherry to the broth. Simmer 10 minutes.
- Season. Taste and add salt only if needed (the beef base is already salty).
- Toast the baguette under the broiler — golden but not burnt.
- Bowl up. Ladle hot soup into oven-safe bowls. Float 2 baguette slices on top and cover with ¾ cup gruyère.
- Broil 2 to 3 minutes, until the cheese is melted and bubbly with golden brown spots.
- Serve immediately, with a warning that the bowls are hot.
Chef’s Tips
- The patience tax: under-cooked onions make a thin, sad soup. They should be deep golden before the broth goes in. The sugar helps, but it isn’t a shortcut.
- Beef base over bouillon for depth — from my restaurant days, Better Than Bouillon gave great results.
- No oven-safe bowls? Toast the bread, top with gruyère, broil on a sheet pan, then float it on the soup.
- Variations: a splash of brandy with the sherry; or a half-mix of red and yellow onions.
- Pair with a small green salad and a glass of dry red wine.
- Scaling: halves easily; doubles cleanly. The hardest part is finding a pot wide enough for the onions to caramelize evenly.
Storage & Make-Ahead
- Soup base keeps 4 days in the fridge — flavors deepen.
- Freezes 2 months without the bread and cheese.
- Reheat gently; add bread and cheese right before serving.
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