Place the chicken breast in a shallow bowl and coat thoroughly with buttermilk; let it marinate for 15 minutes.
In a separate bowl, whisk together the almond flour, 1 tablespoon of arrowroot starch, garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting the excess drip off, then dredge it through the flour mixture until fully coated.
Lightly spray the air fryer basket with avocado oil and cook the chicken at 375°F for 12 to 15 minutes, flipping halfway through, until the exterior is golden and crisp.
While the chicken cooks, melt the ghee in a small saucepan over medium heat.
Whisk the remaining 0.5 teaspoon of arrowroot starch into the chicken bone broth until smooth, then pour it into the saucepan.
Simmer the broth until thickened, then remove from heat and whisk in the Greek yogurt to create a creamy gravy.
Serve the crispy chicken immediately, generously drizzled with the warm gravy.