In saucepan melt 2 tablespoons butter; blend in 3 tablespoons all-purpose flour, 1/2 teaspoon salt, and dash cayenne.
Add 1 cup skim milk; cook and stir till thick and bubbly.
Remove from heat.
Add 4 ounces process Swiss cheese, shredded (1 cup); stir till cheese melts.
Beat 4 egg yolks till thick and lemon-colored.
Add cheese mixture, stirring constantly; cool slightly.
Beat 4 egg whites to stiff peaks.
Pour yolk mixture over whites; fold together thoroughly.
Pour into ungreased 5-cup souffle dish.
For a top hat that puffs in the oven, trace a circle through mixture 1 inch from edge and 1 inch deep.
Bake at 300° till knife inserted off-center comes out clean, about 11/4 hours.
Serve immediately.