Description
A classic French Onion Soup recipe featuring deeply caramelized onions simmered in a rich beef broth, topped with toasted French bread and a blend of melted Gruyere, Parmesan, and Swiss cheeses. This comforting soup combines the sweetness of slow-cooked onions with savory broth and a cheesy, crispy topping, perfect for a cozy meal.
Ingredients
Scale
Onions
- 4 large yellow onions (about 3 pounds), thinly sliced
- 1 yellow onion, roughly chopped (for broth)
- 6 large cloves garlic, smashed
Base & Aromatics
- 4 tablespoons butter (half stick)
- 1 tablespoon kosher salt (use less if using table salt)
- 1/4 teaspoon cayenne pepper (optional)
- 2 tablespoons all purpose flour
- 1/2 cup sherry wine or white wine
- 1 tablespoon fresh lemon juice (about half a lemon)
- 8 cups high quality beef broth
- 2 cups water
- 1 tablespoon Better Than Bouillon Beef Base
- 3 carrots, peeled and roughly chopped
- 2 stalks celery, roughly chopped
- 1 teaspoon prepared horseradish (or more, to taste)
- 3 sprigs fresh thyme (or 1/2 teaspoon dried thyme)
- 3 small sprigs fresh rosemary (or 1/2 teaspoon dried rosemary)
- 3 bay leaves
- 15 peppercorns (about 1/2 teaspoon)
Bread & Cheese Topping
- 1 (1-pound) loaf of French bread, sliced into 1-inch thick slices
- 1 cup Gruyere cheese, freshly grated
- 1 cup Parmesan cheese, freshly grated
- 8 ounces Swiss cheese, sliced
- Freshly chopped chives
- Freshly cracked black pepper
Instructions
- Slice the Onions: Thinly slice about 4 large yellow onions (about 3 pounds) to yield about 8 cups. This ensures even caramelization and makes the soup easier to eat.
- Caramelize the Onions: In a 12-inch, high-sided stainless steel pan, melt 4 tablespoons butter over medium heat. Add the sliced onions, sprinkle with 1 tablespoon kosher salt, and add the cayenne pepper if using. Cook over medium heat for 10 minutes until onions are translucent, stirring occasionally.
- Slow Caramelization: Reduce heat to medium-low and continue cooking the onions for about 90 minutes, stirring every 10-20 minutes, until they are deeply golden and sweet without any raw onion bite, taking care not to scorch them.
- Prepare the Broth: Meanwhile, in a large Dutch oven or stockpot over high heat, combine 8 cups beef broth, 2 cups water, and 1 tablespoon Better Than Bouillon Beef Base. Add the chopped carrots, yellow onion, celery, smashed garlic, horseradish, thyme, rosemary, bay leaves, and peppercorns. Bring to a boil, then reduce heat and simmer covered for about 90 minutes while the onions caramelize.
- Strain the Broth: After simmering, strain the broth through a colander, discarding all solids. Return the clear broth to the pot and keep warm.
- Add Flour and Deglaze: Sprinkle the caramelized onions with 2 tablespoons flour, stirring and cooking for 1-2 minutes to remove any raw flour flavor. Stir in 1/2 cup sherry or white wine, increase heat to medium, and deglaze the pan by scraping up browned bits. Add 1 tablespoon fresh lemon juice and continue cooking until most of the liquid is absorbed.
- Combine Onions and Broth: Transfer the onions and pan juices to the warm broth. Stir well, taste, and adjust seasoning as desired, adding more salt, horseradish, or herbs if needed.
- Prepare the Bread: Preheat oven to 350°F (175°C). Slice French bread into 1-inch thick slices. Arrange on a baking sheet in a single layer and toast for 10 minutes. Flip slices and toast an additional 5 minutes until crisp on both sides. Optionally, butter the slices before toasting for extra richness.
- Assemble the Soup: Grate Gruyere and Parmesan cheeses. Place about 1/2 tablespoon of each cheese into the bottom of seven oven-safe bowls. Ladle the hot soup into the bowls, then top each with a toasted bread slice. Sprinkle more Gruyere and Parmesan cheese on top, then add a slice of Swiss cheese.
- Broil and Serve: Place the bowls on a baking sheet and place on a rack in the upper third of the oven. Broil on high for 2 to 4 minutes until the cheese melts and browns in spots. Remove carefully, garnish with freshly chopped chives and freshly cracked black pepper, and serve immediately. Warn guests the bowls will be hot.
Notes
- Use high-quality beef broth and Better Than Bouillon Beef Base for deep flavor.
- Caramelizing onions slowly over low heat is key to developing the soup’s signature sweetness.
- Toasting the bread well is important to prevent it from becoming soggy in the soup.
- If preferred, use dry white wine instead of sherry for deglazing.
- Fresh herbs enhance flavor but dried herbs can be substituted if fresh are not available.
- Use oven-safe bowls for broiling the cheese topping safely.
- Wear oven mitts when handling hot bowls from the oven to avoid burns.
