Slice the chicken breast into even, thick strips.
Place chicken in a bowl with the buttermilk and let marinate for at least 15 minutes in the refrigerator.
In a shallow dish, whisk together the almond flour, arrowroot powder, smoked paprika, garlic powder, sea salt, and black pepper.
Remove each chicken strip from the buttermilk, letting excess drip off, then dredge in the flour mixture, pressing firmly to ensure a thick coating.
Preheat the air fryer to 400°F and lightly spray the basket with avocado oil.
Arrange chicken in a single layer and air fry for 12-15 minutes, flipping halfway through, until the exterior is golden and crispy.
While the chicken cooks, steam the green beans until tender-crisp, then toss with olive oil and a pinch of salt.