Onion Soup Bistro
["6 to 8 large yellow Spanish onions, thinly sliced", "6 tbsp. butter", "2 tbsp. olive oil", "2 tbsp. flour", "1 1/2 quarts beef stock*", "1 quart chicken stock*", "12 to 16 slices Swiss cheese, (square block)", "6 to 8 slices Italian or French bread", "1 cup dry sherry", "Salt and pepper to taste"]
["*Granulated beef and chicken bouillon may be substituted."]
["yellow Spanish onions", "butter", "olive oil", "flour", "beef stock", "chicken", "Swiss cheese", "Italian", "sherry", "Salt"]