Slice the chicken breast into even strips and place them in a bowl with the buttermilk to marinate for at least 20 minutes.
In a shallow dish, whisk together the almond flour, arrowroot starch, garlic powder, onion powder, paprika, sea salt, and black pepper.
Preheat the air fryer to 400°F and lightly coat the basket with half of the avocado oil.
Dredge each piece of chicken in the flour mixture, pressing firmly to ensure a thick and even coating.
Place the chicken in the air fryer basket in a single layer and spray the tops lightly with the remaining avocado oil.
Air fry for 12-15 minutes, flipping halfway through, until the coating is golden brown and the chicken is cooked through.
While the chicken cooks, steam the green beans in a steamer basket over boiling water until tender-crisp.
Serve the crispy chicken immediately alongside the fresh green beans for a clean and balanced meal.