New Macaroni And Cheese Casserole
["1 (16 oz.) pkg. rigatoni or ziti macaroni", "salad oil", "1 small onion, chopped", "1/3 c. flour", "1 qt. milk", "1/4 tsp. each: salt and pepper", "1/2 lb. Mozzarella cheese, shredded", "1 (10 oz.) pkg. frozen peas", "1/2 lb. cooked ham, diced"]
["Preheat oven to 350\u00b0.", "Prepare macaroni to package directions. Drain macaroni and return to pot."]
["rigatoni", "salad oil", "onion", "flour", "milk", "salt", "Mozzarella cheese", "frozen peas", "ham"]