For cream of chicken: 1/3 cup dry mix + 1 1/4 cups water
For cream of mushroom: same as cream of chicken + 2 oz chopped mushrooms + 1 tsp salt
For cream of celery: same as cream of chicken + 1/8 cup celery flakes or 1/2 cup chopped celery (microwaved until soft).
Combine all ingredients and heat until thickened, stirring constantly.
For use in Casseroles, there is no need to combine the dry mix with liquid before adding to other casserole ingredients. Simply mix the dry ingredients with the dry casserole ingredients, then mix the liquid with the casserole's other liquid ingredients.