1/4 c. butter 3 c. onion, sliced 1 T. sugar 1 t. salt 2 T. all-purpose flour 4 c. beef broth 1/4 c. dry white wine or beef broth 6 slices French bread 1/2 c. grated Parmesan cheese 1/2 c. shredded mozzarella cheese
Melt butter in a skillet over medium heat. Add onion; cook for 15 to 20 minutes, until soft. Stir in sugar and salt; continue to cook and stir until golden. Add flour; mix well. Combine onion mixture, broth and wine or broth in a slow cooker. Cover and cook on high setting for 3 to 4 hours. Ladle soup into oven-proof bowls. Top with bread slices; sprinkle with cheeses. Broil until cheese is bubbly and melted. Serves 6.
