Chopped, granulated, minced or powdered, dried onions are a cookï¿½s necessity. Select at least two grades of coarseness, as recipes call for various forms of onion. Use onion salt only when both flavors are needed. To reconstitute, soak in cold water (3 times their volume) at least 30 min. When enough liquid is present in recipes, add dry flakes toward the end of cooking.