Bring a salted pot of water to a boil. Simmer the chicken until it reaches an internal temperature of 160°. Remove from water and dice into small chunks. Place in the refrigerator to cool fully.
Roasted chickpeas: Preheat the oven to 400 degrees. In a bowl mix all the ingredients. Season with salt and pepper to taste. Place on a baking sheet and roast in the oven until golden brown and crispy but still tender inside, about 10 to 15 minutes. Set aside to cool.
Once the chicken is cooled fully mix it with the celery, onion, yogurt, dill, salt & pepper.
Warm the pita on both sides in a nonstick pan on medium heat.
Place the lettuce, tomato, and chicken salad on the pita. Fold in half. Serve with roasted chickpeas.