1. Soak wooden skewers in water 30 minutes to prevent burning.
2. Thread turkey, peppers, and onions alternately onto skewers. Sprinkle kabobs evenly with Cajun seasoning; lightly coat with cooking spray.
3. 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.