4 tablespoons butter
5 large yellow onions, thinly sliced
1 teaspoon salt
1/2 cup dry red wine
32 ounces beef broth
1 tablespoon Worcestershire sauce
2 sprigs fresh thyme
1 bay leaf
5 1-inch thick slices of French bread
2 tablespoons olive oil
1 1/2 cups shredded Gruyere Swiss cheese,
(room temperature)
1/4 cup shredded Mozzarella cheese, room temperature
