French Onion and Oyster Soup

1. Melt butter in large pot, add onions and cook until soft and translucent.
2. Add oysters and liquor, cook until edges curl.
3. Add broth, sherry, Worcestershire and cook until mixture is hot.
4. To serve, spoon 1 cup of soup into each of 8 bowls and top each serving with 2 tablespoons Swiss cheese and 2 tablespoons Parmesan.
5. Top each bowl with a thin slice of toasted garlic bread if desired.