boil potatoes with skins on let cool. when cool peel potatoes.(we find this much easier after potatoes are cooked.) grate potatoes into a baking dish, that is sprayed with non stick butter spray.
cut cheese into small cubes. melt butter in non stick skillet. add cheese cubes. stir constantly until cheese is creamy. take skillet off heat. add sour cream until mixed well. turn into dish with potatoes.
add onions, salt and pepper and mix well. cover and place in a 350 degree oven for 1hr. remove foil and bake until top is browned.