Preheat oven to 375°; line cookie sheet with aluminum foil. Split franks lengthwise in half but do not cut all the way through; open flat on prepared cookie sheet.
In medium bowl, stir mashed potatoes and frozen vegetables; evenly spoon potato mixture onto franks and sprinkle with cheese. Bake 10 minutes or until hot.
In small saucepot, heat beans over medium heat 5 minutes or until heated through, stirring occasionally; stir in salsa. Serve franks topped with bean mixture.