Classic French Onion Soup with Caramelized Onions, Gruyère, and Crispy Baguette Recipe
This Classic French Onion Soup recipe delivers deeply caramelized onions simmered in rich beef and chicken broth, enhanced with white wine and brandy, then topped with toasted baguette slices and a generous crown of melted Gruyère and Parmesan cheese. This authentic Parisian bistro-style soup is the epitome of comforting elegance, perfect for cozy dinners, dinner parties, or any time you crave a savory, cheesy, soul-warming dish.
- Prep Time: 20 minutes
- Cook Time: 1 hour 30 minutes
- Total Time: 1 hour 50 minutes
- Yield: 6-8 servings 1x
- Category: Dinner, Soup
- Method: Stovetop
- Cuisine: French
Ingredients
Scale
For the Soup
- 4 lbs yellow onions, thinly sliced
- 4 tablespoons unsalted butter
- 2 tablespoons olive oil
- 1 teaspoon salt, plus more to taste
- 1 teaspoon sugar
- 4 cloves garlic, minced
- 1/2 cup dry white wine (or dry sherry)
- 2 tablespoons brandy or cognac (optional but authentic)
- 6 cups beef broth (high-quality)
- 2 cups chicken broth
- 2 bay leaves
- 4–5 sprigs fresh thyme (or 1 teaspoon dried thyme)
- 1 tablespoon Worcestershire sauce
- 1/2 teaspoon black pepper
- Salt to taste
For the Topping
- 1 French baguette, sliced 3/4-inch thick
- 2 tablespoons butter, melted
- 1 clove garlic, halved
- 2 cups Gruyère cheese, shredded (about 8 oz)
- 1/2 cup Parmesan cheese, grated
- Fresh thyme leaves for garnish
Instructions
- Prepare the Onions: Peel and halve the onions from root to stem. Slice each half thinly into approximately 1/4-inch thick half-moons. The onions will cook down significantly during caramelization.
- Start Caramelizing: In a large heavy-bottomed pot or Dutch oven, melt the butter with olive oil over medium heat to prevent butter burning. Add all sliced onions, stirring to coat with the fat. Add salt and sugar to draw out moisture and aid caramelization. Cover and cook for 10 minutes, stirring occasionally to sweat the onions.
- Caramelize the Onions: Remove the lid, reduce heat to medium-low, and cook the onions slowly for 40-50 minutes total. Stir every 5-10 minutes. Add a splash of water if the onions start sticking to deglaze and incorporate those flavorful browned bits. The onions should become deep golden brown and sweetly jammy, the key flavor base of the soup.
- Add Garlic and Wine: Stir in minced garlic and cook for 1-2 minutes until fragrant. Pour in the white wine and brandy (if using), scraping up any browned bits stuck on the pot bottom. Simmer 3-4 minutes until the liquid reduces by half and the alcohol aroma dissipates.
- Build the Broth: Add beef broth, chicken broth, bay leaves, thyme, Worcestershire sauce, and black pepper. Bring to a boil, then reduce heat and simmer uncovered for 30 minutes to meld flavors. Remove bay leaves and thyme sprigs, then taste and adjust salt and pepper as needed.
- Prepare the Bread: Preheat oven to 400°F (200°C). Slice the baguette into 3/4-inch thick rounds. Arrange on a baking sheet and brush both sides with melted butter. Toast for 5-7 minutes per side until golden and crispy. While still warm, rub one side of each slice with the cut side of a garlic clove for subtle garlic flavor. Set aside.
- Assemble the Soup Crocks: Preheat your broiler to high. Arrange 6-8 oven-safe crocks or soup bowls on a baking sheet. Ladle the hot soup into each crock about 3/4 full. Top each with 1-2 toasted baguette slices, pressing gently to float partially submerged. Pile generously with shredded Gruyère cheese, allowing some to cascade down the sides, then sprinkle with grated Parmesan.
- Broil to Golden Perfection: Place the baking sheet under the broiler. Broil for 3-5 minutes, watching carefully to melt and bubble the cheese, developing a golden brown and slightly crusty top. Remove carefully (crocks will be very hot) and let cool 1-2 minutes.
- Serve Immediately: Garnish with fresh thyme leaves if desired and serve with extra toasted baguette slices for dipping. Warn guests that the soup is hot and enjoy the iconic cheese pull with the first spoonful.
Notes
- Caramelization is key; do not rush the 40-50 minute slow cooking of onions to achieve deep flavor.
- Add a splash of water whenever onions start sticking to scrape up flavorful browned bits.
- Use authentic Gruyère cheese for the best melt and flavor; Swiss cheese can be substituted if needed.
- Must use oven-safe crocks to broil the cheese topping safely.
- Soup base can be made up to 3 days in advance (without bread and cheese) and refrigerated or frozen for up to 3 months.
- Toast baguette slices up to one day ahead and keep airtight.
- Watch the broiler carefully—cheese can burn quickly.
- For a vegetarian variation, substitute vegetable broth for beef and chicken broths.
Keywords: French onion soup, caramelized onions, Gruyère cheese soup, classic French soup, comfort food, winter soup, bistro soup, melted cheese soup
