In large saucepan or dutch oven, over medium heat, cook onions and sugar in butter until brown and soft, about 15 - 20 minutes.

Stir in flour until well blended.

Add water, wine, broth, and/or bouillon cubes, heating on high heat until it reaches a boil.  Reduce heat to low, cover, and simmer 10 minutes.  Season to taste.

Cut bread into thick slices (1-1 1/2 inches thick) and toast in 325 degree oven until lightly browned, about 10 minutes.

Ladle soup into oven- or microwave-safe bowls.  Fit slices of bread on top, trimming to cover soup.  Top with slices of cheese, again trimming to cover completely.

Bake at 425 degrees for 10 minutes, or microwave on high for 60-90 seconds, just until cheese is nicely melted.

This makes lots:  anywhere from 3-6 servings, depending on how much you eat!