Add chicken to a large bowl and stir in celery, olives, sundried tomatoes, and feta.
In a small, separate bowl, whisk KRAFT Mayo and GOOD SEASONS Greek Salad Dressing Mix together.
Add this to the chicken mixture and stir until everything is well coated. Cover and place in refrigerator for 2 hours (this helps the flavors blend together!)
When ready to serve, remove from fridge and either place in a serving dish surrounded with pita chips or top individual pita chips with a tablespoon of chicken salad mixture.