1. Prepare cheese sauce: In 2-quart saucepan over low heat, melt butter or margarine. Stir in flour, salt, and ground red pepper until blended; cook 1 minute. Gradually stir in milk; cook, stirring constantly, until mixture thickens slightly. Stir in cheese; cook, stirring, just until cheese melts. Remove saucepan from heat.
2. In small bowl, beat egg yolks slightly; stir in small amount of hot cheese sauce. Gradually pour egg-yolk mixture into cheese sauce in saucepan, stirring rapidly to prevent lumping. Cool slightly.
3. Preheat oven to 325°F. In large bowl, with mixer at high speed, beat egg whites until stiff peaks form. With rubber spatula, gently fold cheese mixture, one-third at a time, into egg whites just until blended.
4. Pour mixture into ungreased 2-quart souffle dish. If desired, with back of spoon, make 1-inch-deep indentation all around in souffle mixture about 1 inch from edge of dish (the center will rise higher than the edge, making a top-hat effect when the souffle is done). Bake 55 to 60 minutes, until knife inserted under top hat comes out clean.