Cut the chicken breast into 1-inch thick strips to ensure even cooking.
Place the chicken strips in a bowl and pour the buttermilk over them, letting them marinate for at least 15 minutes.
In a shallow dish, whisk together the almond flour, arrowroot starch, smoked paprika, garlic powder, onion powder, sea salt, and black pepper.
Remove each chicken strip from the buttermilk, letting the excess drip off, then dredge thoroughly in the seasoned flour mixture.
Preheat your air fryer to 400°F and lightly coat the basket with half of the avocado oil.
Arrange the chicken in a single layer in the basket and drizzle or spray the remaining avocado oil over the top.
Air fry for 12 to 15 minutes, flipping halfway through, until the coating is crispy and the internal temperature reaches 165°F.