French Onion Soup
Slow-caramelized onions in rich beef broth, topped with toasted baguette and a bubbling, browned Gruyère crust.
French onion soup takes patience but very little skill. The onions cook slowly until they're deep brown and sweet, and that's where all the flavor comes from.
The famous cheese crust happens in the last 3 minutes under the broiler, so use oven-safe bowls and keep a close eye on them.
French Onion Soup
Ingredients
For the soup
- 3 lb (1.4 kg) yellow onions, about 5 large, thinly sliced
- 4 tbsp (55 g) unsalted butter
- 1 tbsp olive oil
- 1 tsp salt
- 2 garlic cloves, minced
- ½ cup (120 ml) dry white wine (optional)
- 6 cups (1.4 L) beef broth
- 2 sprigs fresh thyme or ½ tsp dried thyme
- 1 bay leaf
- Black pepper, to taste
For the topping
- 8 slices baguette, ½ inch (1 cm) thick, toasted
- 2 cups (200 g) shredded Gruyère
Instructions
- Melt the butter with the oil in a large, heavy pot over medium heat. Add the onions and salt and stir to coat.
- Cook for 45 to 60 minutes, stirring every few minutes and lowering the heat if they start to scorch, until the onions are soft and deep golden brown.
- Add the garlic and cook for 1 minute. Pour in the wine, if using, and scrape up the brown bits from the bottom of the pot. Simmer until almost evaporated.
- Add the broth, thyme and bay leaf. Simmer gently for 20 minutes. Remove the thyme sprigs and bay leaf, and season with pepper and more salt if needed.
- Heat the broiler with a rack about 6 inches (15 cm) from the heat. Set 4 oven-safe soup bowls on a baking sheet.
- Ladle the soup into the bowls. Float 2 toasted baguette slices on each and cover generously with Gruyère.
- Broil for 2 to 4 minutes, watching closely, until the cheese is bubbling and browned in spots. Use oven mitts; the bowls will be extremely hot.
Tips for success
- Don't rush the onions with high heat. They'll burn before they turn sweet.
- If the onions stick, add a tablespoon of water and scrape. The brown film adds flavor.
- Only use bowls labeled oven- or broiler-safe. Regular ceramic can crack.
Storing and reheating
Refrigerate the soup without the bread and cheese for up to 4 days, or freeze for up to 3 months. Reheat, then add the topping and broil.
Equipment you'll need
- Large heavy pot or Dutch oven
- Oven-safe soup bowls
- Baking sheet
Questions
Can I make it without wine?
Yes. Deglaze with a little extra broth and add 1 teaspoon of balsamic or sherry vinegar at the end for brightness.
Which cheese can replace Gruyère?
Swiss, Comté, Emmental or a mix of Swiss and Parmesan all melt and brown well.
Measurements are given in US cups and spoons with approximate metric weights. Oven temperatures can vary, so check doneness using the signs described in each step. Always check labels if you are cooking for someone with a food allergy.
