In a medium bowl, combine the Greek yogurt, mayonnaise, lemon juice, Dijon mustard, garlic powder, onion powder, and salt and pepper to taste. Whisk until smooth and creamy, then set aside.

In a large mixing bowl, add the cooked chicken, diced apple, chopped celery, sliced green onions, dried cranberries, and toasted pecans. Toss gently to combine.

Pour the dressing over the chicken mixture and mix thoroughly until all ingredients are well-coated. Taste and adjust seasoning if necessary.

Serve immediately or store in an airtight container, keeping pecans separate until serving to maintain crunchiness.