Grease a 9 x 13 glass dish. Put bread in pan. Put sausage on top of bread. Sprinkle a bag of cheese over meat. Mix together eggs, milk, mustard and salt. Pour over cheese. Cover with foil and refrigerate overnight. In the morning before baking, top with cornflakes and then drizzle melter butter over the cornflakes. Bake @ 350 for 45 minutes. Let stand 5 minutes before cutting.