"This may be served hot as a casserole or reduce the melted butter amount down to 2 tablespoons and serve as a cold potato salad, either way it's delicious! --- If you are serving hot as a casserole I strongly recommend to have the potatoes cooled to room temperature before using in this recipe or use cold potatoes that have been cooked a day ahead, I have even made this using about 5 cups of thawed frozen hash browns, the complete casserole may be assembled and refrigerated for up to 2 days ahead before baking although it's so delicious cold it might not even make it to the oven, and also makes a large amount which makes this *perfect* dish for potlucks --- if you are baking as a casserole use only mayonnaise such as Hellman's using salad dressing will not be as good...."