Place the chicken breast in a shallow bowl and cover with buttermilk, letting it marinate for at least 15 minutes.
In a separate small bowl, whisk together the almond flour, arrowroot starch, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting excess drip off, then dredge thoroughly in the almond flour mixture until well-coated.
Lightly coat the air fryer basket with avocado oil and place the chicken inside; air fry at 375°F for 12-15 minutes, flipping halfway through, until golden and cooked through.
While the chicken cooks, prepare the biscuit dough by stirring together the all-purpose flour, Greek yogurt, and baking powder in a bowl until a soft dough forms.
Shape the dough into a tall round and place on a parchment-lined baking sheet; bake in a 400°F oven for 10-12 minutes until the top is lightly browned and fluffy.
Serve the hot air-fried chicken alongside the fresh biscuit immediately.