8 oz. pkg. Creamette shells
4 tbsp. butter
4 tbsp. flour
3 c. milk
2 1/2 c. Cheddar cheese, grated
1/4 c. onion, minced
1 tsp. prepared mustard
1 tsp. salt
1/4 tsp. pepper

Prepare Creamette shells according to package directions. Drain. In a medium saucepan, melt butter. Add flour and cook, stirring constantly, for 2 minutes, do not brown. Stir in milk, cheese, onion, mustard, salt and pepper. Cook until cheese is melted.

Mix shells with sauce. Pour into a 3-quart casserole. Bake in a 350 degree oven for 25 to 30 minutes. 6 to 8 servings.