LINE slow cooker with foil, with ends of foil extending slightly over side. Mix meat, stuffing mix, egg, water and vegetables just until blended; shape into loaf in prepared slow cooker. Cover with lid.
COOK on LOW 6 to 8 hours (or on HIGH 3 to 4 hours).
TOP with pizza sauce and cheese; cook, covered, 10 min. or until cheese is melted. Use foil handles to remove meatloaf from slow cooker before slicing to serve.