Melt the butter in the top of a double boiler, add flour and stir until well blended. Add milk and continue cooking, stirring, until the sauce has thickened. Stir in the grated cheese and heat until the cheese has melted. Add well boned shredded crab meat and heat through. Season to taste with salt and cayenne pepper. Beat egg yolks slightly and add sauce to them. Whisk egg whites stiffly and gently fold mixture into them a little at a time. Pour into a buttered and floured souffle dish set in a pan of hot water. Bake at 325 F for 25 to 30 minutes. Serve at once.{$7e}(Original recipe for 4)