4 lg. white onions, sliced (1-1/2 to 2 lbs.)
1/2 stick butter
2 tablespoon flour
3 (10 to 13 oz.) cans of beef broth
1/2 teaspoon salt
1/4 teaspoon pepper
1/2 cup dry white wine
8-1/2 inch thick slices of French bread, toasted
8 slices Swiss or Mozzarella cheese, optional
Sauté onions in butter in heavy 4 quart saucepan over medium heat. Stir often, until golden, about 20 to 30 minutes. Stir in flour; cook 1 minute. Add beef broth, wine, salt and pepper. Heat to boiling; reduce heat and simmer, partially covered for 30 minutes. Heat broiler. Ladle soup into 4 oven proof 12 to 16 ounce bowls and place on baking sheet. Add 2 slices toasted bread to each and cover with 2 slices of cheese. Broil 6 inches from heat until cheese is bubbly brown and forms a crust. Place bowls on plates and serve at once.