01 - Heat a dry skillet over medium heat, toast pecans for 3–4 minutes stirring frequently until fragrant. Remove from heat and cool.
02 - In a large bowl, mix cooked chicken, celery, green onions, parsley, grapes if using, and the cooled pecans.
03 - In a separate bowl, whisk together mayonnaise, Greek yogurt, Dijon mustard, lemon juice, salt, and black pepper until smooth.
04 - Pour the dressing over the chicken mixture and gently toss to coat evenly.
05 - Taste and adjust salt and pepper as needed.
06 - Refrigerate for at least 20 minutes to allow flavors to meld. Serve on greens, in sandwiches, or with crackers.