In a medium bowl, whisk together the Greek yogurt, mayonnaise, and lemon juice until smooth and creamy. Add dill, parsley, onion powder, and season with salt and pepper to taste. Whisk until well combined, creating a luscious dressing.

In a large mixing bowl, add diced chicken, feta cheese, celery, cucumbers, roasted red peppers, black olives, and red onions. Toss in the dressing, gently folding until well integrated.

Taste your salad mixture and adjust seasoning as needed. Cover with plastic wrap or transfer to an airtight container. Refrigerate for at least one hour.

After chilling, give the salad a gentle stir. Serve on a bed of greens, in wraps, or with crackers.