French Onion Soup Fondue Recipe Type: Appetizer Cuisine: American Author: Prickly Gourmet Prep time: 5 mins Cook time: 20 mins Total time: 25 mins Serves: 4 to 6 servings Ingredients Fondue 2 tablespoons oil 2 large onions, diced 1/2 pound Swiss cheese, grated 1/2 pound Gruyére cheese, grated 2 tablespoons flour 3/4 cup beef broth