Pierogi Casserole
["10 to 12 potatoes, boiled and mashed", "3/4 lb. Cheddar cheese, grated", "2 1/2 sticks margarine or butter", "2 onions, finely diced", "1 lb. lasagne noodles, cooked"]
["Cook lasagne noodles according to package directions. Mash the potatoes.", "Add cheese to the potatoes and beat with mixer.", "Saute onion in margarine until soft. Add 1/3 of the onion and margarine to the potato mixture and salt to taste. Generously butter a 13 x 9 x 2-inch baking dish.", "Place a layer of lasagne noodles in dish, then a layer of potato mixture. Repeat, ending with noodles.", "Pour butter and onion over all.", "Cover with foil and bake at 350\u00b0 until heated through."]
["potatoes", "Cheddar cheese", "margarine", "onions", "lasagne noodles"]