Melt butter, add flour, and gradually hot milk. Bring to boiling point and pour on to yolks of eggs beaten until thick and lemon-colored, and mixed with sugar and salt; cool, and cut and fold in whites of eggs beaten stiff and dry. Turn into buttered pudding-dish, and bake from thirty to thirty-five minutes in slow oven; take from oven and serve at once,—if not served immediately it is sure to fall; serve with Creamy or Foamy sauce.