Place the almonds in a small dry skillet over medium heat and toast, stirring frequently, for 3–5 minutes until golden; remove from heat and set aside to cool.
Remove the skin from the rotisserie chicken and discard the skin and bones; place the cooked meat on a cutting board and roughly chop into bite-sized pieces (about 5 cups).
Chop the celery, dice the apple, and thinly slice the scallions; finely chop the fresh dill.
In a large mixing bowl combine the chopped chicken, mayonnaise, celery, diced apple, sweet pickle relish, toasted almonds, scallions, Dijon mustard, and chopped dill.
Stir thoroughly until all ingredients are evenly coated; taste and season with salt and pepper as needed.
Cover and chill until ready to serve; the flavors improve after resting, so refrigerate for at least an hour or overnight if possible.
