Place the chicken breast in a bowl and pour the buttermilk over it, letting it marinate for at least 15 minutes.
In a shallow dish, whisk together the almond flour, 3 teaspoons of arrowroot powder, sea salt, black pepper, garlic powder, and onion powder.
Remove the chicken from the buttermilk, letting the excess drip off, then dredge it thoroughly in the flour mixture.
Heat the avocado oil in a skillet over medium heat and cook the chicken for 5-6 minutes per side until the coating is golden and crispy.
Remove the chicken from the pan and set aside; whisk the remaining 1 teaspoon of arrowroot powder into the almond milk.
Pour the milk mixture into the hot skillet, whisking constantly to scrape up the browned bits until the gravy thickens into a velvety consistency.
Serve the fried chicken drizzled with the warm gravy.