Make this recipe a recipe that people in that category can eat. categories: ['low_fat'], recipe: in large soup pot over medium heat, melt the butter. add the onions, cover and slowly cook until soft and translucent, stirring occasionally, about 15 minutes. add sugar and continue to cook until caramelized and rich brown in color, about 10 more minutes. add broth, vinegar, and salt and pepper to taste. simmer, covered for 20 minutes. heat broiler. ladle soup into 4 oven proof bowls. top each with a piece of toasted bread and 1/4 of the cheese. broil until cheese is melted and golden. be careful removing bowls from boiler.

Target recipe: sauté onions in butter and oil until onions are transparent, but not well browned. when tender, turn heat to lowest point and sprinkle with flour, stirring vigorously. pour into dutch oven and stir in broths. heat thoroughly and divide among 8 oven-proof bowls. float a slice of bread atop each serving. mix equal parts of each cheese to smooth paste and spread over bread. place all bowls on oven rack 4 inches from broiler heat and broil until cheese melts. serve at once. leftover soup freezes well up to 6 months.