1. Heat oven to 375ºF. Mix butter and mustard in shallow dish until well mixed. Mix bread crumbs and cheese in large plastic bag.
2. Dip one piece of chicken at a time into butter mixture, coating all sides. Then place in bag of bread crumbs, seal bag and shake to coat with crumb mixture. Place chicken in single layer in ungreased rectangular pan, 13x9x2 inches.
3. Bake uncovered 20 to 30 minutes, turning once, until juice of chicken is no longer pink when centers of thickest pieces are cut.