Leftover Macaroni and Ham Casserole

4 tbsp. margarine
1/4 c. minced onion
3 tbsp. flour
1/2 tsp. salt
1/2 tsp. dry mustard
1/4 tsp. paprika
1/8 tsp. pepper
3 c. milk
8 oz. macaroni, cooked and drained
1-1/2 c. diced cooked ham
1/2 c. shredded Cheddar cheese

In 3 quart saucepan melt 2 tablespoons margarine on low heat. Stir in next 6 ingredients until well blended. Remove from heat. Gradually stir in milk until smooth, stirring constantly. Cook over medium heat about 10 minutes or until thickened. In 2 quart casserole arrange alternate layers of macaroni, ham and sauce. Top with cheese. Dot with remaining margarine. Bake in 375 F. oven 20 to 25 minutes or until bubbly.