Slather leftover lamb slices with Special Mustard Sauce for quick and tasty sandwiches.
Stir together first 4 ingredients in a small bowl. Rub mixture over lamb, and place in a shallow roasting pan.
Bake lamb at 425° for 45 minutes; reduce oven temperature to 375°, and bake 20 minutes or until a meat thermometer inserted into thickest portion registers 155°. Let lamb stand for 20 minutes before serving.