Italian Stuffed Rigatoni
["1 c. chopped onion", "3 Tbsp. olive oil", "2 (6 oz.) cans tomato paste", "1 (1 lb. 13 oz.) can plum tomatoes", "4 c. water", "1 Tbsp. sugar", "1 Tbsp. salt", "1/2 tsp. pepper", "1 bay leaf", "1/2 tsp. oregano", "3/4 lb. rigatoni", "3/4 c. bread crumbs", "1 lb. sausage, chopped", "1/3 c. milk", "1/3 c. grated Italian cheese", "1 egg"]
["Saute onion in hot oil until soft; add tomato paste, tomatoes and water; stir well.", "Add seasonings, cover and simmer 1 hour, stirring occasionally.", "While sauce is cooking, cook rigatoni in 5-quarts of salted water for 10 minutes.", "Drain; rinse with cold water; drain well.", "Remove casing from sausage; break up meat and brown well.", "Add bread crumbs, milk and egg; mix well.", "Stuff each rigatoni with filling.", "Layer sauce and rigatoni into large casserole dish.", "Sprinkle with cheese.", "Bake in moderate oven (350\u00b0) for 35 to 45 minutes.", "Serve at once."]
["onion", "olive oil", "tomato paste", "tomatoes", "water", "sugar", "salt", "pepper", "bay leaf", "oregano", "rigatoni", "bread crumbs", "sausage", "milk", "Italian cheese", "egg"]