Ingredients:
4 large onions, thinly sliced
4 tablespoons unsalted butter
2 tablespoons olive oil
4 cups beef broth
2 cups chicken broth
1/2 cup dry white wine (optional)
1 teaspoon Worcestershire sauce
1 teaspoon balsamic vinegar (optional)
1 teaspoon sugar
Salt and black pepper to taste
Baguette slices, toasted
Gruyère or Swiss cheese, grated
:
In a large pot, melt the butter with olive oil over medium heat. Add the sliced onions and cook, stirring occasionally, for about 30-40 minutes until they turn golden brown and caramelized.
Sprinkle sugar over the onions and continue to cook for an additional 5 minutes, stirring occasionally.
Pour in the white wine (if using), scraping the bottom of the pot to deglaze.
Add beef broth, chicken broth, Worcestershire sauce, and balsamic vinegar (if using). Season with salt and black pepper to taste. Bring to a gentle simmer and let it cook for 20-25 minutes.
Preheat the oven broiler. Ladle the soup into oven-safe bowls. Place a few toasted baguette slices on top of each bowl and generously sprinkle with grated Gruyère or Swiss cheese.
Place the bowls on a baking sheet and broil in the oven until the cheese is melted and bubbly, about 2-3 minutes.
Carefully remove from the oven and let it cool for a minute before serving.
Prep Time: 10 minutes | Cooking Time: 1 hour | Total Time: 1 hour 10 minutes
Servings: 4 servings