1. Soak wooden skewers in water 30 minutes to prevent burning.
2. Whisk together peanut butter, water, soy sauce, brown sugar, garlic, lime rind, and red pepper flakes. Place chicken in a large zip-top plastic bag; pour peanut butter mixture over chicken. Seal bag, and chill at least 30 minutes or up to 4 hours. Remove chicken from marinade, discarding marinade.
3. Thread chicken, peppers, and onions alternately onto skewers. Sprinkle kabobs evenly with seasoned pepper; lightly coat with cooking spray.
4. Grill kabobs, covered with grill lid, over medium heat (300° to 350°) 6 to 8 minutes on each side or until done. Garnish, if desired.