Ingredients
Scale
- 5 large yellow onions, thinly sliced
- 4 tablespoons unsalted butter
- 1 teaspoon sugar (helps with caramelization)
- 2 cloves garlic, minced
- 8 cups beef broth (you can use chicken or vegetable broth for a lighter version)
- 1/2 cup dry white wine (optional)
- 1 bay leaf
- 1/2 teaspoon dried thyme
- Salt and black pepper, to taste
- 1 baguette, sliced
- 1 1/2 cups grated Gruyère cheese (or a mix of Gruyère and Swiss)
- Fresh parsley, chopped for garnish (optional)
Instructions
- Caramelize the Onions:
- In a large pot or Dutch oven, melt the butter over medium heat. Add the onions and sprinkle with sugar.
- Cook the onions, stirring frequently, until they are deeply caramelized and golden brown, about 30-40 minutes. This slow cooking process is key to developing the soup’s rich flavor.
- Deglaze and Simmer the Soup:
- Add the minced garlic to the caramelized onions and cook for another 1-2 minutes until fragrant.
- Pour in the white wine (if using) and scrape any browned bits off the bottom of the pot.
- Add the beef broth, bay leaf, and thyme. Bring the mixture to a simmer and let it cook for about 30 minutes to blend the flavors. Season with salt and pepper to taste.
- Prepare the Bread and Cheese:
- While the soup simmers, toast the slices of baguette until they are golden and crisp.
- Sprinkle each slice with Gruyère cheese and broil in the oven until the cheese is bubbly and slightly browned.
- Assemble and Serve:
- Remove the bay leaf from the soup. Taste and adjust seasoning if necessary.
- To serve, ladle the hot soup into bowls. Top each bowl with one or two cheesy baguette slices.
- Garnish with chopped parsley if desired.
