French Onion Soup

2 large yellow sweet onions, halved and sliced
2 large red onions, halved and sliced
3 tablespoons butter
3 cups low-sodium beef broth
1 cup dry white wine
1 ounce cognac
1 bay leaf
4 sprigs thyme
4 slices bread
4 ounces gruyere or Swiss cheese, grated
1 ounce parmesan cheese, grated
salt and pepper

1. Melt butter in a large skillet over medium heat. Add the onions in batches with a few pinches of salt to release their moisture.
2. Cover and cook until the onions have completely caramelized (turned brown) and reduced considerably, about 1 hour.
3. Once onions have reduced, stir in white wine and cognac and raise heat enough to bring to a boil.
4. Stir in beef broth and add bay leaf and thyme. Reduce heat to a simmer.
5. Meanwhile, cut circles out of the bread, tracing around an ovenproof bowl or dish that you will bake the soup in.
6. Place the bread circles on a baking sheet and toast them directly under the oven broiler.
7. Remove the bay leaf and thyme sprigs and divide the onion soup into bowls, top with a bread circle and a portion of the cheese.
8. Put the bowls on the baking sheet and set under the broiler just until the cheese has melted. Serve immediately.

Makes 4 servings