French Onion Soup

4 onions
2 tablespoons butter
2 cans beef broth
1 soup can water
1 teaspoon Worcestershire sauce
Toasted bread
4 thick slices Swiss cheese

Cook onion in butter. Add broth, water and Worcestershire sauce. Cover and simmer for 20 minutes. Season with salt and pepper. Pour into bowls. Float bread and top with cheese. Broil until the cheese melts.