Au Gratin Potatoes II

Preheat oven to 350 degrees F (175 degrees C). Spray one 8 inch square baking dish with vegetable cooking spray.
In a large bowl, stir together the sour cream and soup. Add grated potatoes, cheese, and onions. Mix well, and pour into the prepared baking dish. Cover the dish with a lid or aluminum foil.
Bake for 45 minutes in the preheated oven. In a small bowl, mix together the melted butter and cornflakes. Sprinkle over the top of the potatoes, and return to the oven.
Bake uncovered, for an additional 20 minutes or until bubbly and corn flakes are golden brown. Remove from the oven and sprinkle with chopped parsley.