French Onion Soup with Gruyere Cheese Toasts Recipe
This classic French Onion Soup recipe features deeply caramelized onions simmered in a rich beef broth, topped with toasted baguette slices smothered in melted Gruyere cheese and garnished with fresh thyme. Perfectly roasted under the grill to achieve a bubbly, golden cheese crust, this comforting soup combines savory depth and cheesy indulgence for a heartwarming meal.
- Prep Time: 15 minutes
- Cook Time: 1 hour 20 minutes
- Total Time: 1 hour 35 minutes
- Yield: 4 servings 1x
- Category: Soup
- Method: Stovetop
- Cuisine: French
Ingredients
Scale
Sauce Base
- 90 g (6 tbsp) unsalted butter
- 1 tbsp oil
- 6 medium yellow/brown onions (about 1.2 kg/2.6 lbs), peeled, halved and thinly sliced
- 1/2 tsp salt
- 1 tsp black pepper
- 3 cloves minced garlic
Flavour & Thickening
- 180 ml (3/4 cup) white wine
- 2 tbsp plain (all-purpose) flour
- 1.5 litres (a splash over 6 cups) good quality strong beef stock
- 1 tbsp Worcestershire sauce
Toppings
- 1 small baguette, sliced into 2 cm (3/4 inch) slices (we need 8 slices)
- 100 g (1 packed cup) grated Gruyere cheese
- Fresh thyme leaves for garnish
Instructions
- Prepare the onions: Add the butter and oil to a large Dutch oven or heavy-based saucepan and heat over medium-low heat until the butter has just melted. Add the sliced onions, salt, and pepper.
- Caramelize the onions: Cook the onions uncovered for about 45-50 minutes. Stir occasionally at first, then frequently during the last 15-20 minutes to avoid burning. The onions should become golden brown and deeply caramelized.
- Add garlic and cook briefly: Stir in the minced garlic and cook for one minute while stirring.
- Deglaze with white wine: Pour in the white wine to deglaze the pan, scraping up all browned bits. Increase the heat to medium-high and cook for 5-8 minutes, stirring often, until almost all the wine has evaporated and the aroma subsides.
- Add flour: Reduce heat to medium and stir in the flour. Cook for one minute, stirring constantly to combine and thicken slightly.
- Add stock and Worcestershire sauce: Pour in the beef stock and Worcestershire sauce, stir well, then bring the mixture to a boil over medium-high heat.
- Simmer the soup: Lower heat to a simmer, cover with a lid, and cook for 30 minutes. Taste and adjust salt as needed.
- Prepare cheese croutons (Method 1): When soup is nearly done, ladle it into grill-safe bowls, top each bowl with two slices of baguette, then sprinkle grated Gruyere evenly on top. Place bowls on a tray and grill for 2-4 minutes until cheese is melted and bubbling. Carefully remove from grill, garnish with fresh thyme, and serve.
- Prepare cheese croutons (Method 2): Alternatively, toast baguette slices on both sides under the grill until lightly browned. Sprinkle each slice with Gruyere and return to the grill until cheese melts and bubbles. Ladle soup into bowls, place two cheese toasts on top, garnish with thyme, and serve.
Notes
- Use a good quality strong beef stock for the best flavor.
- Watch the onions carefully during caramelization to prevent burning, turning heat down as needed.
- Both methods for melting cheese on the baguette are delicious; choose your preferred way.
- Gruyere melts beautifully and adds authentic flavor, but Swiss cheese is a suitable substitute if needed.
- The soup can be made ahead and reheated gently before adding the cheese topping.
Keywords: French Onion Soup, caramelized onions, beef broth soup, Gruyere cheese soup, classic French soup, comforting soup recipe
