The recipe yield is:
Mix potatoes, cheese and dry onion. Saute raw onions in margarine and butter. Grease 2-quart casserole. Layer ingredients as follows: 1/3 of elbows, 4 slices cheese, 1/3 of potato mixture and 1/2 of onions. Repeat two more times, ending with potato mixture. Dot with butter, sprinkle with Parmesan cheese and bake at 350 degrees for 30 minutes.