How to make an easy Soufflé: Heat undiluted soup, cheese, added variation ingredient and seasonings, stir until cheese melts. Beat 6 egg yolks until thick, slowly beat into cheese mixture. Beat 6 egg whites with 1/4 teaspoon cream of tartar until stiff. Fold yolk mixture into whites. Pour into greased 2 quart soufflé dish. Bake at 350ºF. for 40 minutes