Restaurant-Style French Onion Soup
Ingredients:
-
½ cup butter
-
8 onions, sliced
-
2 cloves garlic, crushed
-
½ teaspoon salt, or to taste
-
½ teaspoon ground black pepper, or to taste
-
1 teaspoon dried thyme
-
1 cup red wine
-
1 tablespoon sherry
-
2 tablespoons all-purpose flour
-
2 quarts beef broth
-
1 French baguette, cut into 1/2-inch thick slices
-
olive oil, or as needed
-
6 slices Swiss cheese
-
6 slices provolone cheese