Toast the walnuts in a small pan over low heat for 3-5 minutes. Remove from the heat and set aside.
⅓ cup chopped walnuts
In a small bowl, combine the mayonnaise, mustard, lemon juice, salt, and pepper.
⅔ cup mayonnaise, 3 teaspoons Dijon mustard, 3 teaspoons freshly squeezed lemon juice, ¼ teaspoon ground black pepper, ½ teaspoon salt
In a separate bowl, combine the chicken, cranberries, celery, walnuts, and onion. Add the dressing, and stir to combine.
3 cups cooked chicken, ½ cup dried cranberries, ⅓ cup thinly sliced celery, ¼ cup finely diced red onion
Refrigerate until ready to serve. Serve as-is, on croissants, on sliders, in a wrap, or as a sandwich.