Cut the chicken breast into even strips or nuggets.
Place chicken in a bowl with buttermilk and let marinate for at least 20 minutes in the refrigerator.
In a shallow dish, whisk together the arrowroot powder, almond flour, smoked paprika, garlic powder, onion powder, sea salt, and black pepper.
Remove each piece of chicken from the buttermilk, letting excess drip off, then dredge thoroughly in the flour mixture.
Preheat your air fryer to 400°F and lightly coat the basket with avocado oil.
Arrange chicken in a single layer and mist the tops with the remaining avocado oil.
Air fry for 12-15 minutes, flipping halfway through, until the coating is golden and the chicken is cooked through.
While chicken cooks, steam the green beans until tender-crisp and serve alongside the hot chicken.