Description
Classic French Onion Soup is a rich, deeply flavorful soup made by slowly caramelizing sweet yellow onions, simmering them in a savory beef broth with sherry and herbs, then topped with toasted baguette slices and melted Gruyère cheese for a perfect finish. This hearty and comforting soup is ideal as an appetizer or a light meal on cooler days.
Ingredients
Scale
Sauté and Soup Base:
- 2 Tbsp olive oil (plus more to brush toasts)
- 2 Tbsp unsalted butter
- 3 lbs yellow onions (about 6 large onions, halved, peeled and thinly sliced with the grain)
- 1/2 tsp granulated sugar
- 2 garlic cloves (minced)
- 1/2 cup dry sherry wine (or use dry vermouth or dry white wine)
- 8 cups beef stock (or broth)
- 1 bay leaf
- 3 sprigs fresh thyme (plus more to garnish, or 1/4 tsp dried thyme)
- 1 1/2 tsp salt (or to taste, divided)
- 1/2 tsp black pepper (or to taste)
For Toast and Cheese Topping:
- 12 slices baguette
- 8 oz Gruyère cheese (1 1/2 cups shredded, divided)
Instructions
- Caramelize the Onions: Heat 2 tablespoons olive oil and 2 tablespoons butter in a large heavy-bottomed pot over medium-low heat. Add the sliced yellow onions and granulated sugar, cooking slowly for about 45-60 minutes until they turn a deep golden brown and develop a rich caramelized flavor. Stir frequently to prevent burning.
- Add Garlic and Deglaze: Stir in the minced garlic and cook for about 1 minute until fragrant. Pour in the dry sherry to deglaze the pan, scraping up any brown bits from the bottom with a wooden spoon. Let the liquid reduce slightly for 2-3 minutes.
- Simmer the Soup: Add the beef stock, bay leaf, thyme sprigs, 1 teaspoon salt, and black pepper to the pot. Bring to a gentle simmer, cover partially, and let cook for about 30 minutes, allowing flavors to meld. Taste and adjust seasoning with the remaining 1/2 teaspoon salt as needed. Remove bay leaf and thyme sprigs before serving.
- Prepare Toasts: While the soup simmers, preheat the oven to 400°F (200°C). Arrange baguette slices on a baking sheet and brush lightly with olive oil. Toast in the oven for 8-10 minutes until crisp and golden. Remove and set aside.
- Assemble and Broil: Ladle the hot soup into oven-safe bowls. Place toasted baguette slices on top of each bowl and sprinkle generously with shredded Gruyère cheese. Place bowls under the broiler for 3-5 minutes, watching closely until the cheese bubbles and turns golden brown.
- Garnish and Serve: Optionally sprinkle with fresh thyme leaves for garnish. Serve the French Onion Soup immediately while hot and the cheese is melted and gooey.
Notes
- Be patient when caramelizing onions; slow cooking intensifies their natural sweetness and flavor.
- If you prefer a vegetarian version, substitute beef stock with vegetable broth.
- Dry sherry can be replaced with dry white wine or dry vermouth depending on availability.
- Gruyère cheese is traditional for this recipe, but Swiss or mozzarella can be used as substitutes with a milder flavor.
- Use oven-safe bowls to broil the cheese topping safely.
- Adjust salt and pepper to taste at the end to balance flavors.
