Cook chicken breasts (boil, bake, or grill) until fully done (165°F internal temp). Let cool, then shred using forks or a hand mixer.
Finely dice celery and red onion. If using grapes or nuts, prepare them now.
In a large bowl, whisk together mayonnaise, Greek yogurt, Dijon mustard, lemon juice, honey, salt, and pepper.
Add shredded chicken, celery, red onion, and optional add-ins (grapes/almonds) to the dressing. Mix gently until well coated.
Taste and add more salt, pepper, or lemon juice if needed. Stir in fresh parsley.
Refrigerate for at least 30 minutes before serving. Enjoy on bread, croissants, or over lettuce.
