In a 4-quart saucepan (or small stockpot) over medium heat, melt the butter and add onions until translucent. Add sugar and continue sauteeing until the onions brown and caramelize about 10 to 15 minutes. Stir in flour until well blended with the onions and any pan juices (add a smidge of the vegetable broth if there aren't any pan juices). Add wine and vegetable broth and bring to a boil. Reduce heat and simmer for 10 to 20 minutes allowing the soup to thicken slightly. Meanwhile (in another part of the kitchen), cut four 1-inch thick slices of bread from loaf; save remaining bread to eat with soup. Toast the bread slices in 325-degree F oven just until lightly browned, about 10 minutes. Ladle soup into four 12-ounce oven-safe bowls and place one slice of toasted bread on surface of soup in each bowl. Top each bowl of soup with Swiss cheese slices. Place soup bowls on a jelly-roll pan for easier handling. Bake in 425-degree F oven for 10 minutes or just until cheese is melted and bubbly. The Good Housekeeping Illustrated Cookbook by Good Housekeeping ISBN: 068808074X DISCLAIMER: This is a not-for-profit website and these recipes appear as a courtesy to my veg*n friends around the world. No copyright infringement is intended. At the request of the copyright holder(s), the recipe(s) will be promptly removed.