A very tasty dish that you can do ahead of time and pop into the oven at the last minute. Good for a buffet.
Boil the potatoes in salted water to cover until tender. Mash or rice. While still hot, add the sour cream, cottage cheese, onion, butter or margarine, pepper and salt. Mix well.
Place in a casserole. Sprinkle Parmesan on top. Bake in a 325 degree oven for 30 minutes.