French Onion Soup Recipe – Rich Caramelized Onion Soup with Gruyère & Toasted Baguette
This Rich and Simple French Onion Soup is a timeless classic that delivers deep flavor with minimal effort. Slowly caramelized onions are simmered in a savory beef broth, then topped with crusty baguette slices and melted Gruyère cheese for a comforting finish. Perfect for chilly evenings, dinner parties, or a cozy starter, this soup is elegant, satisfying, and surprisingly easy to make. Serve with a glass of red wine and enjoy the warmth of French bistro-style dining at home.
Equipment
- Large heavy-bottomed pot or Dutch oven
- Wooden spoon
- Oven-safe soup crocks or ramekins
- Baking sheet
- Cheese grater
- Broiler or oven with broil setting
Ingredients
- 4 large yellow or sweet onions, thinly sliced
- 2 tbsp unsalted butter
- 1 tbsp olive oil
- 6 cups beef broth (or 4 cups beef + 2 cups chicken broth)
- ½ cup dry white wine or sherry
- 2 cloves garlic, minced
- 1 tsp fresh thyme (or ½ tsp dried)
- 1 bay leaf
- 1 baguette, sliced into ½-inch rounds
- 1½ cups grated Gruyère (or Swiss/provolone)
- Optional: 1 tbsp Worcestershire sauce or 2 tbsp brandy
- Salt and freshly ground black pepper, to taste
Instructions
- Caramelize the Onions In a large pot, heat butter and olive oil over medium-low heat. Add sliced onions and a pinch of salt. Cook slowly, stirring often, for 30–40 minutes until onions are deeply golden and caramelized. Don’t rush—this step builds the soup’s flavor.
- Deglaze and Simmer Add garlic and cook for 1 minute. Pour in wine or sherry to deglaze the pot, scraping up browned bits. Add thyme, bay leaf, broth, and optional Worcestershire or brandy. Bring to a simmer and cook uncovered for 20–30 minutes. Season with salt and pepper.
- Prepare the Toppings While the soup simmers, preheat the oven to 400°F (200°C). Toast baguette slices on a baking sheet until golden and crisp, about 8–10 minutes. Grate the cheese.
- Assemble and Broil Preheat broiler. Ladle hot soup into oven-safe crocks. Top each with a toasted baguette slice and a generous handful of cheese. Place crocks on a baking sheet and broil 2–3 minutes until cheese is bubbly and golden.
Notes
- For best results, use low and slow heat when caramelizing onions—rushing leads to bitterness.
- Use high-quality broth for a rich, savory base. Homemade or low-sodium store-bought are ideal.
- Don’t overload the cheese—a thick layer can overwhelm the soup.
- Make ahead tip: Caramelize onions a day in advance and refrigerate.
- Vegetarian option: Use vegetable broth and skip Worcestershire sauce.
- No wine? Substitute with extra broth or a splash of white wine vinegar.
- Prevent soggy bread by toasting well and broiling just before serving.