mixture aside.
combine the egg, 2/3 cup milk, and biscuit mix; beat with rotary beater till blended but still slightly lumpy. bake batter on hot, lightly greased griddle using about 3 tablespoons mixture for each pancake (makes 8 pancakes). place half of the pancakes in a shallow baking pan. spread each with about a fourth of the chicken mixture. top with remaining pancakes. cover tightly. seal, label, and freeze.
before serving: bake frozen stack-ups, covered, in 350° oven for 35 to 40 minutes. meanwhile, in saucepan melt the butter or margarine; blend in the flour, salt and pepper. add the 1 cup milk all at once. cook and stir over medium heat 