The recipe yield is:
Preparation : Cook lasagna noodles according to package directions. Mash potatoes; add cheese to potatoes and beat with a mixer. Saute onions in butter until tender. Add 1/3 of onions and butter to potato mixture and salt to taste. Generously butter 9 x 13 inch baking dish. Place a layer of noodles in dish, then a layer of potato mixture. Repeat ending with a layer of noodles. Pour remaining butter and onions on top. Cover with foil and bake at 350 degrees until heated through.