Caramelized French Onion Soup
A comforting soup made with slowly caramelized onions, topped with Gruyère cheese and broiled to perfection, perfect for cozy evenings.
Ingredients
Main ingredients
- 4 large onions, thinly sliced Yellow or sweet onions work best.
- 4 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1 teaspoon salt
- 1 teaspoon sugar Helps accelerate caramelization.
- 8 cups beef or vegetable broth Beef for classic flavor; vegetable for vegetarian.
- 1/2 cup dry white wine Optional; adds brightness.
- 1 tablespoon fresh thyme or 1 teaspoon dried thyme
- to taste salt and pepper
- 2 cups shredded Gruyère cheese Comté or Swiss is a fine substitute.
Instructions
Preparation
- Heat a large pot over medium. Add the butter and olive oil until the butter melts.
- Add all the sliced onions, 1 teaspoon salt, and 1 teaspoon sugar. Stir to coat.
- Cook slowly, stirring every 5–10 minutes. Keep the heat at medium to medium-low so the onions brown, not burn. This takes about 30–40 minutes.
- If using wine, pour it in now. Scrape the browned bits off the bottom of the pot to deglaze. Let the wine cook off for about 5 minutes.
- Add the broth, thyme, and bay leaf. Season lightly with pepper and a touch more salt if needed. Bring the soup to a simmer.
- Simmer gently for another 30 minutes to marry the flavors. Remove the bay leaf. Taste and adjust seasoning.
Broiling
- Preheat your broiler.
- Ladle the soup into oven-safe bowls. Top each bowl with a baguette slice, then pile on the shredded Gruyère.
- Place the bowls under the broiler until the cheese is bubbly and golden brown, 2–3 minutes. Watch closely to prevent burning. Serve immediately.
Notes
For a vegetarian soup, use a rich vegetable broth and skip the beef stock. If you don’t have Gruyère, a mix of Swiss and Parmesan can work; avoid very wet cheeses.