In a large mixing bowl, combine Greek yogurt, shredded cucumber, lemon juice, chopped dill, garlic powder, salt, and pepper. Stir vigorously for about 1-2 minutes until well-blended.

Add shredded chicken, finely chopped red onion, kalamata olives, crumbled feta cheese, and chopped parsley to the tzatziki sauce. Gently fold the mixture with a spatula for 1-2 minutes.

Taste and adjust seasoning with additional salt, pepper, or lemon juice. Stir again for another 30 seconds.

Transfer the salad to a serving bowl and garnish with extra dill, feta, or olive oil. Chill in the refrigerator for 15-30 minutes before serving.

Serve chilled or at room temperature, paired with warm pita bread or on a bed of mixed greens.