By Chef B. Boukim
Prep: 20 min · Cook: 60 min · Total: 80 min · Serves 6
Ingredients
- 5 large Large yellow onions, thinly sliced
- 4 tbsp Unsalted butter
- 1 tbsp Olive oil
- 1/2 cup Dry white wine
- 8 cups Vegetable broth
- 4 sprigs Fresh thyme sprigs
- 2 Bay leaves
- 1 tbsp Worcestershire sauce
- 1 tsp Salt
- 1/2 tsp Black pepper
- 6 slices French baguette, sliced 1-inch thick
- 2 cups Gruyere cheese, grated
- 1/2 cup Parmesan cheese, grated
Instructions
- Melt butter with olive oil in a large heavy-bottomed pot over medium heat. Add the sliced onions and salt.
- Cook the onions for 40-50 minutes, stirring frequently, until deeply caramelized and dark brown. Reduce heat if they begin to burn.
- Pour in the white wine and scrape up browned bits. Simmer for 2-3 minutes until the wine has mostly evaporated.
- Add the vegetable broth, thyme sprigs, bay leaves, and Worcestershire sauce. Bring to a boil, then reduce to a simmer.
- Simmer uncovered for 15-20 minutes to meld flavors. Season with salt and pepper. Discard thyme and bay leaves.
- Preheat the broiler. Toast the baguette slices on both sides until golden.
- Ladle the soup into oven-safe bowls. Place a baguette slice on top, then generously cover with Gruyere and Parmesan.
- Place under the broiler for 2-3 minutes until the cheese is melted, bubbly, and golden brown. Serve immediately.