Combine the shredded chicken, finely chopped celery, halved grapes, and chopped pecans in a large mixing bowl.
In a separate bowl, whisk together the sour cream, mayonnaise, fresh dill, salt, and pepper until well blended. Pour this creamy mixture over the chicken mixture and stir thoroughly to ensure all ingredients are evenly coated.
Cover the bowl and refrigerate the salad for at least 2 hours, allowing the flavors to meld together. This delicious chicken salad can be served in a variety of ways, including on bread, in a salad, wrapped in a tortilla, or with pretzel crackers for a satisfying crunch.