Ingredients
Soup:
- 3 tablespoons unsalted butter, cut into 3 pieces
- 6 large yellow onions, about 4 pounds, halved and cut into ¼-inch thick slices
- Table salt, to taste
- 2 cups (500 ml) water, plus extra for deglazing
- ½ cup (120 ml) dry sherry
- 4 cups (940 ml) chicken broth
- 2 cups (480 ml) beef broth
- 6 sprigs fresh thyme, tied with kitchen twine
- 1 bay leaf
- Ground black pepper, to taste
Cheese Croutons:
- 1 small baguette, cut into ½-inch slices
- 8 ounces (226.8 g) shredded Gruyere cheese, about 2½ cups
Instructions
- Caramelize the Onions: In a large heavy-bottomed pot or Dutch oven, melt the butter over medium heat. Add the sliced onions and a generous pinch of salt. Cook, stirring occasionally, until the onions are deeply golden and caramelized, about 40-50 minutes.
- Deglaze the Pot: Add a splash of water to the pot and scrape the bottom with a wooden spoon to loosen any browned bits. Pour in the dry sherry and bring to a simmer, allowing the alcohol to cook off and flavors to meld, about 3-5 minutes.
- Add Broths and Herbs: Stir in the chicken broth, beef broth, thyme sprigs tied with twine, and bay leaf. Bring the soup to a gentle boil, then reduce heat and simmer uncovered for 30 minutes to develop a rich flavor.
- Season the Soup: Remove the thyme bundle and bay leaf. Taste the soup and season with additional salt and ground black pepper as needed.
- Prepare Cheese Croutons: While the soup is simmering, preheat the oven to 400°F (205°C). Arrange the baguette slices on a baking sheet and toast them in the oven until golden and crispy, about 5-7 minutes.
- Add Cheese and Broil: Spoon the hot soup into oven-safe bowls. Place toasted baguette slices on top of each bowl and generously sprinkle shredded Gruyere cheese over the bread. Place the bowls on a baking sheet and broil in the oven until the cheese is melted, bubbly, and slightly browned, about 2-4 minutes. Watch carefully to prevent burning.
- Serve: Carefully remove the hot bowls from the oven and serve the French Onion Soup immediately, allowing the melted cheese and savory broth to delight your palate.
Notes
- Use a heavy-bottomed pot or Dutch oven to ensure even caramelization of onions.
- Carefully watch the soup while broiling to avoid burning the cheese.
- For a vegetarian version, substitute vegetable broth for the chicken and beef broth.
- Dry sherry adds depth, but you can substitute with dry white wine or omit if preferred.
- Leftover soup can be refrigerated for up to 3 days and reheated gently on the stovetop.
- Prep Time: 15 minutes
- Cook Time: 1 hour 15 minutes
- Category: Soup
- Method: Stovetop
- Cuisine: French
