Macaroni and Cheese

1 to 1 1/2 cups uncooked elbow macaroni, rigatoni or spinach egg noodles (about 6 oz)
1/4 cup butter
1/4 cup onion, chopped
1/2 teaspoon salt
1/4 teaspoon pepper
1/4 cup flour
1 3/4 cups milk
8 oz sharp cheddar cheese, cut into 1/2 inch cubes

Cook macaroni as directed.  Cook and stir butter, 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 ungreased 1 1/2 quart casserole dish.  Stir cheese sauce into macaroni.  Cook uncovered in 375 degree oven for 30 minutes.  5 servings.

Note:  I got this recipe from Cherise :-).