1Preheat oven to 350 degrees. Grease 9 X 13-inch baking dish. 2Combine potatoes, soup, sour cream, onion, 1/2 cup butter and salt & pepper; spoon into prepared baking dish. 3Sprinkle cheese on top of potato mixture. 4Combine 1/4 cup melted butter with crushed corn flakes; sprinkle over top of casserole 5Bake for one hour.