Time

1 hour 45 minutes

Ingredients

3 tbsp olive oil
7 tbsp butter
10 cups thinly sliced onions (3 lbs)
5 thyme sprigs, tied in bundle
8 cloves garlic, thinly sliced
2 tbsp all-purpose flour
1 1/4 cups dry red wine
6 cups beef broth
1 1/2 tbsp soy sauce
4 large croissants, cut into cubes
3/4 pound Gruyere or Swiss cheese, grated

Instructions

1. In a Dutch oven, heat the oil and butter over high heat. Add the onions and thyme and cook, stirring often, about 15 minutes. Reduce the heat to medium-low, add the garlic, and cook, another 20 minutes stirring often until evenly golden brown.
2. Add the flour and cook, stirring, until it coats all the onions, about 3 minutes. Add the wine, increase the heat to medium, bring to a boil, about 5 minutes. Discard the thyme bundle. Add the broth, soy sauce, and 1 teaspoon salt. Bring to a boil over high heat, reduce the heat again, and cook at a gently simmer, about 45 minutes. Season to taste.
3. Preheat the oven to 350F. Arrange the croissant pieces on a large baking sheet and bake until golden, about 9 minutes. Remove from the oven and raise the heat to broil.
4. Arrange 6 oven-proof bowls on a baking sheet. Mound on cheese at the bottom of each bowl, ladle soup over cheese, and top with croissant croutons and more cheese. Broil until the cheese is bubbling and slightly browned, 3-4 minutes.