Description
This classic French Onion Soup recipe features deeply caramelized onions simmered in a rich, flavorful beef broth, topped with toasted French bread and a blend of melted Gruyere, Parmesan, and Swiss cheeses. Perfect for a cozy meal, this soup balances sweet, savory, and cheesy elements with an aromatic herb-infused broth.
Ingredients
Scale
Onions and Butter
- 4 large yellow onions (about 3 pounds), thinly sliced
- 4 tablespoons butter (half stick)
- 1 tablespoon kosher salt (use less if using table salt)
- 1/4 teaspoon cayenne pepper (optional)
Thickening and Flavor Enhancers
- 2 tablespoons all purpose flour
- 1/2 cup sherry wine or white wine
- 1 tablespoon fresh lemon juice (about half a lemon)
Broth Ingredients
- 8 cups high quality beef broth
- 2 cups water
- 1 tablespoon Better Than Bouillon Beef Base
- 3 carrots, peeled and roughly chopped
- 1 yellow onion, roughly chopped
- 2 stalks celery, roughly chopped
- 6 large cloves garlic, smashed
- 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 and Cheese Toppings
- 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 approximately 8 cups, ensuring even caramelization and easy consumption in the soup.
- 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 cayenne pepper if using. Cook, stirring occasionally, for about 10 minutes until onions turn translucent.
- Slow Caramelization: Reduce heat to medium-low and continue cooking the onions for about 90 minutes, stirring every 10-20 minutes, until they become deeply golden, sweet, and free of any raw onion bite, avoiding scorching edges.
- Prepare the Broth: 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 carrots, chopped onion, celery, smashed garlic, horseradish, thyme, rosemary, bay leaves, and peppercorns. Bring to a boil, then reduce to a simmer, covered with a vented lid, while onions caramelize, simmering for about 90 minutes.
- Strain the Broth: Once both the onions are caramelized and the broth has simmered sufficiently, strain the broth through a colander, discarding all solids, and return the clear, seasoned broth to the pot to keep warm.
- Add Flour and Deglaze: Sprinkle the caramelized onions with the 2 tablespoons of flour, stirring constantly and cooking for 1 to 2 minutes to eliminate any raw flour taste. Add sherry or white wine, increase heat to medium, and deglaze the pan by scraping up browned bits. Stir in fresh lemon juice and cook until most of the liquid is absorbed.
- Combine Onions and Broth: Transfer the caramelized onion mixture and any pan juices into the warm broth. Stir well, then taste and adjust seasoning with additional salt, horseradish, or herbs as desired.
- Prepare the Bread: Preheat the oven to 350°F (175°C). Slice the French bread into 1-inch thick slices. Arrange the slices in a single layer on a baking sheet and toast in the oven for 10 minutes, then flip and toast an additional 5 minutes until both sides are crisp. Optionally, lightly butter the slices before toasting for extra richness.
- Assemble the Soup: Grate the Gruyere and Parmesan cheese. Place about 1/2 tablespoon of each cheese at the bottom of 7 oven-safe bowls. Ladle the soup into the bowls, place a toasted bread slice on top of each, sprinkle generously with more Gruyere and Parmesan, and top with a slice of Swiss cheese.
- Broil and Serve: Place the filled bowls on a baking sheet and transfer to the oven rack set in the upper third. Broil on high for 2 to 4 minutes, until the cheese is melted and browned in spots. Remove carefully, garnish with freshly chopped chives and cracked black pepper, and serve hot, warning guests that the bowls will be very hot.
Notes
- Use a high-sided pan to caramelize the onions evenly and prevent splattering.
- Slow caramelization is key to developing the soup’s characteristic sweetness and depth of flavor.
- Adjust salt levels based on the type of salt used and personal preference.
- Butter the bread slices before toasting for an even richer topping, if desired.
- Be cautious when broiling the cheese-topped bowls to avoid burning.
- This soup is best served immediately while the cheese is warm and gooey.
