PREHEAT oven to 350ºF. Place chicken in medium bowl. Add 1/2 cup of the mustard; toss to coat.
PLACE peanuts in shallow dish. Add chicken, one piece at a time; turn to evenly coat chicken with the peanuts. Place in single layer on greased baking sheet.
BAKE 20 to 25 min. or until chicken nuggets are cooked through and golden brown. Serve as dippers with the remaining 1/4 cup mustard.