French Onion Soup - Au Gratin

3 large Spanish or Bermuda Onions, thinly sliced
6 T. butter or margarine
5 10 1/2-oz. cans condensed beef broth
1/2 c. dry sherry
3 T. and 1 t. Worcestershire sauce
freshly ground pepper
6 slices French or rye bread, 1/2 inch thick, toasted
3/4 c. grated Parmesan cheese
6 slices Gruyere or Swiss cheese

In large saucepan or Dutch oven, cook onion in butter until tender, but not brown, about 20 minutes.
Add beef broth, sherry, Worcestershire sauce and pepper, bring to a boil.
Pour into 6 individual oven-proof bowls.
Float a slice of bread in each bowl (rub toast with a cut clove of garlic, if desired) sprinkling with Parmesan cheese and top with Gruyere or Swiss cheese slice.
Bake in 375° oven for 15 minutes, or boil till cheese is bubbly, about 5 minutes.
This soup freezes well.

Unknown serving size