Cook sausage and drain. Tear bread into bite sized pieces and put in a greased 9X13 pan. Put cheese on top of bread. Put cooked sausage on top of cheese. Mix eggs, dry mustard and milk together. Pour over breakfast. Cover and refrigerate overnight. Bake in preheated 325 degree oven loosely covered for 30 minutes. Remove foil and bake for 15 additional minutes. Enjoy!