Slice the chicken breast into even strips and place them in a bowl with the buttermilk to marinate for at least 15 minutes.
In a shallow dish, whisk together the almond flour, arrowroot starch, garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Remove each chicken strip from the buttermilk, letting the excess drip off, then dredge thoroughly in the flour mixture until well coated.
Lightly grease the air fryer basket with avocado oil and arrange the chicken in a single layer, ensuring the pieces do not touch.
Air fry at 400°F for 10-12 minutes, flipping halfway through, until the coating is golden brown and the chicken is cooked through.
While the chicken cooks, steam the green beans for 5-6 minutes until they are bright green and tender-crisp.
Serve the crispy chicken immediately alongside the steamed green beans for a balanced, clean-eating meal.