Macaroni and Cheese

1 to 1½  cups un-cooked elbow macaroni

¼ cup margarine or butter

1 small onion, chopped

½ teaspoon salt

¼ teaspoon pepper

¼ cup all purpose flour

1¾ cups milk

8-Ounces processed sharp American or Swiss cheese, process American cheese loaf or processes cheese spread loaf, cut into 12-inch cubes

Cook macaroni as directed on package. Cook and stir margarine, onion, salt and pepper over medium heat until onion is slightly tender. Blend in flour. Cook over low heat stirring constantly, until mixture is smooth and bubbly; remove from heat. Stir in milk. Heat to boiling, stirring constantly. Boil and stir 1 minute, remove from heat. Stir in cheese until melted. Place macaroni in un-greased 1½-quart casserole dish. Stir cheese sauce into macaroni. 

Bake uncovered in 375* oven 30 minutes.

* Garden Macaroni and Cheese: Stir 1 package (10-ounces) frozen green peas or green beans into cheese sauce.

* Ham Macaroni and Cheese: Stir 1 cup cut-up fully cooked smoked ham into cheese sauce.

* Hot Dog Macaroni and Cheese: Stir 1 cup sliced frankfurters (about 3) or cut-up luncheon meat into cheese sauce.

*Olive Macaroni and cheese: Stir ¼ cup chopped pimiento-stuffed olives into cheese sauce.

* Pepper Macaroni and Cheese: Stir 1/3 cup chopped green and /or red peppers or 1 can (4 ounces) green chilies, drained and chopped, into cheese sauce.

* Tomato Macaroni and Cheese: Stir ¼ cup sliced ripe olives into macaroni in casserole. Arrange 1 large tomato, cut into 5 slices, around edge of casserole before cooking.

* Tuna Macaroni and Cheese:  Stir 1 can (6½-ounces) tuna drained, into cheese sauce.