Cream shortening with sugar, egg yolks and milk. When mixture is lukewarm, add yeast. Beat egg whites until stiff, and fold into batter. Add flour and salt. Knead well. Cover and let rise for 1 hour in a warm place. Roll in small pieces and shape into rings. let stand until they begin to rise. Drop bagel into simmering water, one at a time, and cook for 2 or 3 minutes. Place on a greased baking sheet. Bake at 425¼F about 15 minutes, until golden brown. Salt, poppy or sesame seeds may be sprinkled on bagels before baking, if desired. Yield: about 3 1/2 dozen.