In a small bowl, combine the cornstarch, cranberry juice and mustard until smooth; set aside. Sprinkle pork with lemon-pepper. In a large skillet, cook pork in butter for 4-5 minutes on each side or until no longer pink. Remove pork and keep warm.
Stir cornstarch mixture and add to the skillet. Bring to a boil. Add cherries and preserves; cook and stir for 2 minutes or until thickened. Return pork to the pan; cook for 2 minutes or until heated through.