Slice the chicken breast into even strips or nuggets.
In a small bowl, submerge the chicken in buttermilk and let it marinate for at least 15 minutes.
In a separate shallow dish, whisk together the arrowroot powder, garlic powder, onion powder, paprika, sea salt, and black pepper.
Remove each piece of chicken from the buttermilk, letting the excess drip off, and dredge thoroughly in the seasoned arrowroot mixture.
Preheat your air fryer to 400°F and lightly coat the basket with half of the avocado oil.
Place the chicken in the basket in a single layer, ensuring they do not touch, and drizzle or spray the remaining avocado oil over the top.
Air fry for 10-12 minutes, flipping halfway through, until the coating is golden brown and crispy.
While the chicken cooks, whisk together the Dijon mustard and raw honey in a small ramekin.
Serve the hot chicken immediately with the honey mustard sauce on the side.