French Onion Soup with Caramelized Onions and Gruyère Croutons Recipe
This classic French Onion Soup recipe offers a rich and cozy experience filled with deeply caramelized onions, savory beef broth, and perfectly melted Gruyère cheese atop crispy toasted baguette slices. It's the ultimate comfort food, ideal for chilly days and satisfying meals.
- Prep Time: 10 minutes
- Cook Time: 50 minutes
- Total Time: 1 hour
- Yield: 4 servings
- Category: Soup
- Method: Stovetop
- Cuisine: French
Ingredients
Soup
- ¼ cup unsalted butter
- 5 yellow onions, thinly sliced
- 4 cloves garlic, finely chopped
- 2 bay leaves
- 3-4 fresh thyme sprigs
- Kosher salt and freshly ground black pepper, to taste
- 1 cup red wine
- 3 tablespoons all-purpose flour
- 2 quarts beef broth
Topping
- 1 baguette, sliced
- ½ pound grated Gruyère cheese
Instructions
- Caramelize the Onions: Melt the butter in a large pot over medium heat. Add the sliced onions, garlic, bay leaves, thyme sprigs, and season with salt and pepper. Cook slowly until the onions are very soft, deep golden, and caramelized, about 25 minutes, stirring occasionally to prevent burning.
- Deglaze with Wine: Pour in the red wine and bring to a boil. Reduce heat and simmer until the wine evaporates and the onions are dry, about 5 minutes. Remove and discard the bay leaves and thyme sprigs.
- Cook the Flour: Sprinkle the flour over the caramelized onions and stir well. Lower the heat to medium-low to avoid burning and cook for 10 minutes to cook out the raw flour taste.
- Add Broth and Simmer: Pour in the beef broth and bring the soup back to a gentle simmer. Cook uncovered for 10 minutes, then season with salt and pepper to taste.
- Prepare the Gruyère Toasts: Preheat the broiler. Arrange the baguette slices in a single layer on a baking sheet and top each slice with the grated Gruyère cheese. Broil until the cheese is bubbly and golden brown, about 3 to 5 minutes, watching closely to prevent burning.
- Serve: Ladle the hot soup into oven-safe bowls. Float the Gruyère toasts on top of each serving. Optionally, garnish with fresh thyme leaves before serving.
Notes
- Use oven-safe bowls, ramekins, or mini crocks for broiling the cheese to get a perfect golden crust safely.
- Patience is key with caramelizing onions; cook them low and slow until soft and jammy for best flavor.
- For added depth, mix different types of onions such as yellow, sweet, and red onions.
- When adding wine, scrape the browned bits from the pan to enrich the soup’s flavor.
- If avoiding alcohol, substitute red wine with balsamic vinegar or extra beef stock.
- Gruyère cheese melts beautifully and offers a nutty, savory flavor. Swiss or Emmental cheese are good substitutes.
- Lightly toast the bread before adding cheese to prevent sogginess once placed in the soup.
- This soup improves with time and can be made ahead; reheat gently and add fresh toasts before serving.
- Finish with a sprinkle of fresh thyme leaves for brightness.
