Description
This classic French Onion Soup recipe features deeply caramelized onions slow-cooked to perfection, combined with a rich, flavorful beef broth infused with fresh herbs and aromatics. Topped with toasted French bread and a blend of Gruyere, Parmesan, and Swiss cheeses, then broiled until golden and bubbly, it delivers a warm, comforting, and savory bowl of soup perfect for any occasion.
Ingredients
Scale
Onions and Caramelization
- 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)
- 2 tablespoons all purpose flour
- 1/2 cup sherry wine or white wine
- 1 tablespoon fresh lemon juice (about half a lemon)
Broth and Seasoning
- 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 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 (approximately 3 pounds) to yield about 8 cups, ensuring even caramelization and a smooth texture in the soup.
- Caramelize the Onions: In a 12-inch, high-sided stainless steel pan, melt 4 tablespoons of butter over medium heat. Add the sliced onions, then sprinkle with 1 tablespoon kosher salt and cayenne pepper if using. Cook over medium heat for about 10 minutes until the onions become translucent, stirring occasionally to prevent burning.
- Slow Caramelization: Lower the heat to medium-low and continue cooking the onions for approximately 90 minutes. Stir every 10 to 20 minutes, ensuring the onions turn a deep golden brown and develop a sweet, rich flavor without any burnt edges.
- Prepare the Broth: While the onions cook, combine 8 cups of beef broth, 2 cups water, and 1 tablespoon Better Than Bouillon Beef Base in a large Dutch oven or stockpot over high heat. Add chopped carrots, onion, celery, smashed garlic, horseradish, fresh thyme, rosemary, bay leaves, and peppercorns. Bring the mixture to a boil, then reduce heat and simmer covered with a vented lid for about 90 minutes, in parallel with the onion caramelization.
- Strain the Broth: Once the broth and onions are ready, strain the broth through a colander to remove the vegetables and herbs. Discard the solids and return the clear broth to the pot; keep it warm on low heat.
- Add Flour and Deglaze: Sprinkle 2 tablespoons of flour over the caramelized onions, stirring and cooking for 1 to 2 minutes to eliminate the raw flour taste. Pour in 1/2 cup sherry or white wine and increase heat to medium, scraping up any browned bits from the pan. Add 1 tablespoon fresh lemon juice and cook until most of the liquid has absorbed.
- Combine Onions and Broth: Transfer the caramelized onions and any pan juices into the warm broth. Stir thoroughly, 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 them on a baking sheet in a single layer, and toast them for 10 minutes. Flip each slice and toast for another 5 minutes until both sides are crisp. Optionally, brush slices with butter before toasting for extra richness.
- Assemble the Soup: Grate Gruyere and Parmesan cheeses. In 7 oven-safe bowls, place about 1/2 tablespoon of each shredded cheese at the bottom. Ladle the hot soup evenly into the bowls, top each with a toasted bread slice, then sprinkle more Gruyere and Parmesan cheese on top and finish with a slice of Swiss cheese.
- Broil and Serve: Place the prepared bowls on a baking sheet and position them on the upper third rack of the oven. Broil on high for 2 to 4 minutes, watching closely, until the cheese melts and bubbles with golden brown spots. Carefully remove the bowls, garnish with freshly chopped chives and freshly cracked black pepper, and serve immediately. Warn guests that the bowls will be hot.
Notes
- Slow caramelization of the onions is key to developing deep, sweet flavors without burning.
- If you prefer a milder soup, omit the cayenne pepper and horseradish.
- Use high-quality beef broth for the best flavor. Homemade broth will enhance the richness.
- Toast bread slices thoroughly to prevent sogginess when added to the soup.
- Broil the cheese topping under close supervision to avoid burning.
- This soup can be prepared a day in advance; store broth and onions separately and assemble before serving.
- For a vegetarian variation, substitute beef broth and beef base with vegetable broth and omit horseradish if desired.
- Prep Time: 20 minutes
- Cook Time: 1 hour 30 minutes
- Category: Soup
- Method: Stovetop
- Cuisine: French
