If not using pre-cooked chicken, boil or grill 2 chicken breasts (seasoned with salt & pepper) until fully cooked (165°F internal temp). Shred or dice.
In a dry skillet, lightly toast walnuts/pecans over medium heat for 2-3 minutes until fragrant. Chop roughly.
In a large bowl, combine chicken, grapes, celery, red onion, and nuts.
In a small bowl, whisk mayonnaise, lemon juice, Dijon mustard, salt, and pepper.
Pour dressing over the chicken mixture. Gently toss to coat.
Refrigerate for at least 30 minutes before serving for best flavor.
Enjoy as a sandwich filling, with crackers, or over a bed of lettuce.
