Place the chicken breast in a bowl with buttermilk and marinate for at least 30 minutes in the refrigerator.
In a shallow dish, whisk together the whole wheat flour, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, allowing excess to drip off, then dredge in the flour mixture, pressing firmly to ensure a thick, even coating.
Preheat your air fryer to 375°F and lightly coat the basket with half of the avocado oil.
Place the chicken in the basket and spray or brush the top with the remaining avocado oil.
Air fry for 12-15 minutes, flipping halfway through, until the exterior is golden-brown and the internal temperature reaches 165°F.
While the chicken cooks, whisk the honey and Dijon mustard together in a small bowl to create the glaze.
Steam the green beans until tender-crisp and serve them alongside the chicken, drizzling the honey-mustard glaze over the top of the crispy breast.