Melt butter or margarine in a 4 quart saucepan. Stir in sugar. Cook onions over medium heat for 10 minutes, or until golden brown.
Stir in flour until well blended with the onions and pan juices. Add water, wine, and beef broth and Spices; heat to boiling. Reduce heat to low. Cover soup, and simmer for 10 minutes.
Cut four 1 inch thick slices of bread from the loaf. Toast the bread slices at 325 degrees F (165 degrees C) just until browned, about 10 minutes. Reserve the remaining bread to serve with the soup.
Ladle soup into four 12 ounce, oven-safe bowls. Place 1 slice toasted bread on top of the soup in each bowl. Fold Swiss cheese slices, and fit onto toasted bread slices. Place soup bowls on a cookie sheet for easier handling.
Bake at 425 degrees F (220 degrees C) for 10 minutes, or just until cheese is melted