Description
A classic French Onion Soup recipe featuring caramelized yellow onions simmered in rich beef broth, topped with toasted French baguette slices and melted Gruyère cheese. Perfectly balanced with earthy thyme and subtle bay leaf flavors, this comforting soup is browned under the broiler for a deliciously cheesy crust.
Ingredients
Scale
Soup Base
- 4 large yellow onions (Approximately 2 to 2.5 pounds, firm and golden)
- 4 tablespoons unsalted butter (for caramelizing the onions)
- 1 tablespoon olive oil (prevents butter from burning)
- 1 teaspoon sugar (enhances caramelization)
- 8 cups beef broth (use low-sodium for better control of saltiness)
- 1 teaspoon dried thyme (adds earthy flavor)
- 1 bay leaf (infuses subtle herbal flavor)
- Salt and pepper (to taste)
Toppings
- 8 slices French baguette (crusty bread for topping)
- 2 cups grated Gruyère cheese (melts beautifully and adds nutty flavor)
Instructions
- Prepare Onions: Peel and slice the onions thinly, approximately 1/4 inch thick, to ensure even caramelization and tender texture.
- Sauté Onions: Melt the butter and olive oil in a large pot over medium heat. Add the sliced onions and stir to coat evenly with the fat.
- Caramelize: Sprinkle sugar over the onions, reduce heat to medium-low, and cook slowly for 30-40 minutes, stirring occasionally, until onions turn a deep golden brown and develop a rich caramelized flavor.
- Add Herbs: Stir in dried thyme and the bay leaf, cooking for an additional minute to release their aromas.
- Simmer: Pour in the beef broth, scraping the bottom of the pot to deglaze and lift up browned bits. Bring to a simmer, season with salt and pepper to taste, and let simmer gently for 20 minutes to blend flavors.
- Toast Bread: Meanwhile, preheat the oven to 400°F (200°C). Arrange baguette slices on a baking sheet and toast for 5-7 minutes until golden and slightly crisp.
- Assemble Bowls: Remove the bay leaf from the soup. Ladle the hot soup into oven-safe bowls, top each with toasted baguette slices, and sprinkle generously with grated Gruyère cheese.
- Broil Cheese: Place bowls under a preheated broiler for 2-5 minutes until the cheese is melted, bubbly, and lightly browned.
- Serve: Remove from oven carefully, let cool slightly, garnish with a sprig of thyme if desired, and serve immediately for best flavor and texture.
Notes
- Be patient with caramelizing the onions—it’s the key to deep flavor.
- Using low-sodium beef broth allows better control over final seasoning.
- Gruyère cheese provides the best melt and flavor but Swiss or Emmental can be substitutes.
- Use oven-safe bowls for broiling the cheese topping to avoid cracking.
- To make it vegetarian, substitute beef broth with mushroom or vegetable broth.
