Place the chicken breast in a shallow bowl and pour the buttermilk over it, ensuring it is fully coated. Marinate for at least 20 minutes.
In a separate small bowl, whisk together the almond flour, arrowroot powder, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting the excess drip off, then dredge it thoroughly in the almond flour mixture, pressing to adhere.
Preheat your air fryer to 375°F. Lightly spray the chicken with olive oil and air fry for 12-15 minutes, flipping halfway through, until the internal temperature reaches 165°F and the crust is golden brown.
While the chicken cooks, whisk together the honey, Dijon mustard, and apple cider vinegar in a small ramekin to create the glaze.
Steam the green beans for 5-6 minutes until tender-crisp and toss with the remaining teaspoon of olive oil.
Slice the chicken and drizzle the honey-mustard glaze over the top. Serve immediately alongside the steamed green beans.