1 14.5oz. box of elbow macaroni
3 tbsp. low fat margarine or butter
3 tbsp. all purpose flour
2 1/2 cups skim milk
1/2 tsp. salt
1/8 tsp. pepper
2 cups or 8 oz. reduced fat cheddar cheese
Cook pasta according to package. Preheat oven to 350 degrees. In a medium saucepan, melt margarine. Stir in flour. Gradually, stir in milk. Cook, stirring constantly over medium heat, until sauce thickens. Stir in salt and pepper. Add cheese; stir until cheese melts. Stir cheese sauce into elbow macaroni. Spoon into a greased (I use nonstick spray) 8x8 baking dish. Bake 30 minutes.
The pictures didn't come out very good, but everyone knows what mac and cheese looks like.