Dice or shred the turkey into bite-sized pieces.
In a large bowl, combine turkey, apple, celery, onion, cranberries, and walnuts.
Stir in mayonnaise until everything is evenly coated.
If the mixture feels dry, gradually add chicken stock, 1 tablespoon at a time, until you reach your desired consistency.
Chill for 20–30 minutes before serving for best flavor.