Heat oven to 375°. Combine soup, milk, and salt in a 1 1/2-quart casserole. Add chicken and peas or peas and carrots. Bake for 10 minutes.
Meanwhile, in mixing bowl, beat egg whites until stiff. In another bowl with same beaters, beat egg yolks; stir in cheese. Gently fold yolk-cheese mixture into whites. Pile onto the chicken casserole and bake 25 to 30 minutes longer.
Calories per serving: 293