In a medium bowl, combine the Greek yogurt, grated cucumber, lemon juice, garlic, dill, parsley, salt, and pepper. Stir until well combined.
Add the chicken, diced cucumber, celery, red onion, and feta. Stir until well combined. Taste and add a little more lemon, salt, and pepper, if necessary.
You can serve over greens, with pita chips, in a pita pocket, in a lettuce cup, or make a sandwich or wrap. Feel free to top with chopped tomatoes, kalamata olives, extra feta, and herbs.
