If not using pre-cooked chicken, season 2 chicken breasts with salt & pepper, then pan-fry or bake until fully cooked (165°F internal temp). Shred or dice.
In a large bowl, combine chicken, celery, red onion, grapes, and nuts.
In a small bowl, whisk mayo, yogurt, Dijon, lemon juice, honey (if using), salt, and pepper.
Pour dressing over chicken mixture and gently fold until well-coated.
Stir in fresh parsley.
Refrigerate for at least 30 minutes before serving for best flavor.
Enjoy on croissants, bread, lettuce wraps, or over a bed of greens.
