Place the cooked chicken, chopped grapes, diced celery, red onion, pecans, and parsley into a large mixing bowl.
In a separate smaller bowl, vigorously combine the Greek yogurt, lemon juice, Dijon mustard, sea salt, garlic powder, and black pepper until a smooth dressing forms.
Pour the prepared dressing over the chicken mixture and fold gently with a spatula or spoon until all ingredients are well coated and integrated.
Refrigerate for a short time to chill before serving. Enjoy as a standalone dish, in lettuce wraps, on toast, or with crackers.