Place the chicken breast in a bowl with the buttermilk and let it marinate for at least 30 minutes in the refrigerator.
In a separate shallow dish, whisk together the almond flour, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk and dredge it through the almond flour mixture, pressing firmly so the coating sticks.
Lightly coat the air fryer basket with avocado oil and place the chicken inside, spraying the top of the chicken with the remaining oil.
Air fry at 375°F for 12 to 15 minutes, flipping halfway through, until the crust is golden and the internal temperature reaches 165°F.
While the chicken cooks, whisk the chicken bone broth and arrowroot powder in a small saucepan over medium heat until it begins to simmer and thicken.
Remove the gravy from the heat and stir in the Greek yogurt until smooth and creamy.
Serve the crispy chicken topped with the warm gravy alongside steamed green beans.