Preheat oven to 350 degrees.  In a large mixing bowl combine melted butter, sour cream and chicken soup stirring until mixture is creamy.  Slowly start folding in hashbrowns, onions and shredded cheese.  Add salt and pepper to taste.  Spray a 9x13" baking dish with cooking spray.  Pour mixture into baking dish and bake uncovered for 40-45 minutes.  Top off casserole with Fried onions and continue to bake for another 5-10 minutes.  Remove from oven and allow to cool 5 minutes before serving.

My family does not like the texture of onions in their food so I replace all my recipes that call for onion with onion powder.  A few hefty shakes is usually enough for this casserole.