Prepare potatoes. Melt butter in large saucepan. Add flour and blend. Gradually add the milk and cook until thick. Add remaining ingredients and stir until cheese melts. Add potatoes and stir well. Pour into a greased casserole dish. Bake, uncovered, at 350 degrees F for 25-30 minutes. until top is browned. cook's notes for best results use whole milk and butter. No substitutes. Can top with buttered soft bread crumbs.