(from Belleville restaurant)
1/4 cup butter
3 yellow onions, thinly sliced
4 Vidalia onions, thinly sliced
1 teaspoon white sugar
1 tablespoon all-purpose flour
2-1/2 cups water
1/2 cup red wine
6 cups beef broth
1 French baguette, sliced into big croutons
8 ounces sliced Swiss cheese or gruyere
Preheat oven to 325 degrees. Melt butter in a four-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; heat to boiling. Reduce heat to low. Cover, and simmer for 10 minutes.
Cut four one-inch thick slices of bread from the loaf and toast in the oven until browned (about 10 minutes). Reserve the remaining bread to serve with the soup. Ladle soup into four, 12-ounce, oven-safe bowls. Place one slice of toasted bread on top of the soup in each bowl. Place Swiss cheese slices on each toasted bread slice.
Raise oven temperature to 425 degrees and bake for three minutes or just until cheese is melted.