In a medium bowl, combine Greek yogurt, reduced fat mayonnaise, fresh dill, and fresh parsley. Squeeze in lemon juice and add onion powder along with salt and pepper to taste. Stir until the dressing is smooth and creamy, then set it aside.

In a large mixing bowl, add cooked, shredded chicken, crumbled feta cheese, diced celery, chopped Persian cucumbers, and chopped roasted red peppers. Toss in sliced black olives and diced red onions. Pour the Greek yogurt dressing over the top and mix gently until all ingredients are well-coated.

Taste the salad to see if it needs any adjustments like additional salt, pepper, or lemon juice. Mixing well is crucial for flavor.

Cover the bowl with plastic wrap or transfer the salad to an airtight container. Place in the refrigerator and let it chill for at least 1 hour.

After chilling, remove the salad from the fridge and give it a gentle mix before serving. Serve on a bed of mixed greens, in a wrap, or enjoy it on its own!