Place the chicken breast between two sheets of parchment paper and pound to an even half-inch thickness.
Place the chicken in a shallow bowl and pour the buttermilk over it, ensuring it is well coated; let it marinate for 10 minutes.
In a separate shallow dish, whisk together the almond flour, one tablespoon of arrowroot starch, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting any excess drip off, then dredge it thoroughly in the flour mixture, pressing to adhere.
Heat the avocado oil in a medium skillet over medium heat. Once hot, add the chicken and cook for 5-6 minutes per side until the crust is golden brown and the internal temperature reaches 165°F.
While the chicken cooks, steam the green beans in a small pot with a splash of water until tender-crisp, about 5 minutes.
Remove the chicken from the skillet and set aside to rest. In the same skillet, whisk together the bone broth, almond milk, and the remaining teaspoon of arrowroot starch.
Simmer the sauce over medium-low heat, scraping up any browned bits from the pan, until the gravy thickens into a creamy consistency.
Plate the chicken alongside the steamed green beans and drizzle the warm gravy over the top.