Crockpot French Onion Soup

6 Onions, thinly sliced
1 Clove garlic, minced
3 Tablespoons butter
30 Ounces beef broth
1 Cup water
1 1/2 Teaspoon Worcestershire sauce
1/8 Teaspoon pepper
8 Slices French bread
8 Slices Swiss cheese

Saut� onions in butter over medium heat until tender. Combine all ingredients except bread and cheese in crockpot. Cover; cook on LOW for 6 to 8 hours or on HIGH for 3 to 4 hours. Toast bread slices; top each with a slice of cheese and place under broiler until cheese is golden. Place one slice of bread in each bowl; ladle soup over top.