One-dish dinners save you time on every step from menu planning to cleanup. Here are some tips to make casseroles even easier.

BUY INGREDIENTS THE WAY YOU USE THEM- Loosepack frozen vegetables; pre-shredded cheese; boneless chicken breasts or frozen cooked chicken, cubed; precooked sausages; cooked canned garbanzo, pinto and kidney beans can help save time in the kitchen.

MAKE USE OF YOUR MICROWAVE

- Cook chopped onion, celery and green pepper, covered, in margarine or water in the microwave.

- Cook ground beef in the microwave. Drain well before combining with other ingredients.

- Cook pasta and rice on the rangetop while vegetables and sauces cook in the microwave.

- Try giving your favorite casseroles their final cooking in the microwave. Cook, covered, on 100 percent power (high) for about one-fourth to one-third of the oven baking time. Check for doneness, turn, and add cooking time 2 minutes at a time. Add cheese or crumb toppings when the casserole is done.

FIXING FOR A FREEZE

- Use converted rice in casseroles destined for the freezer. It retains a firm texture even after freezing.

- Cook pasta for freezer casseroles just until it's almost tender. Rinse it with cold water to halt the cooking. It will finish cooking when you bake the frozen casserole.

- Don't settle for a square of foil over the top of a casserole intended for the freezer. Overwrap completely with heavy-duty foil to keep air and moisture out.

- To keep your baking dishes free for cooking, wrap make-ahead recipes this way: Cut a length of heavy-duty foil three times the width or diameter of the dish. Line the dish with the foil. Add the food and cool. Bring the longer sides of the foil together over the food. Fold down the foil, pressing air out, until the foil is next to the food. Fold down shorter sides. Freeze until firm; then lift out the wrapped food. Label and store in the freezer. When you're ready to reheat, remove the foil and return the frozen food to the original dish.

- If the recipe includes an acid ingredient such as a tomato product, wrap the food first in clear plastic wrap, then overwrap with foil. Remove the plastic wrap before baking.

- Freeze casseroles up to 3 months. Label and date each package when you freeze it.

INGREDIENT SUBSTITUTIONS

- For thickening, 2 tablespoons flour equals 1 tablespoon cornstarch.

- 3/4 cup tomato paste plus 1 cup water equals 2 cups tomato sauce.

- 1/2 cup tomato sauce plus 1/2 cup water equals 1 cup tomato juice.

- 1 tablespoon prepared mustard equals 1 teaspoon dry mustard.

- 1 teaspoon onion powder or 1 tablespoon dried minced onion equals 1 small onion.

POTLUCKS

- To keep a casserole hot until you reach a potluck dinner, wrap it in foil or a heavy towel and place in a plastic-foam container. Pack the casserole as soon as you take it from the oven.