Place the chicken breast in a bowl with the buttermilk and let it soak for 15 minutes to tenderize.
In a shallow dish, whisk together the 2 tablespoons of arrowroot powder, sea salt, black pepper, garlic powder, onion powder, and paprika.
Remove the chicken from the buttermilk, allowing any excess to drip off, and dredge it thoroughly in the seasoned arrowroot mixture.
Heat the avocado oil in a skillet over medium heat and cook the chicken for 5 to 6 minutes per side until the exterior is golden and the center is cooked through.
Remove the chicken from the skillet and set it aside on a plate to rest.
In the same skillet, whisk in the almond milk and the remaining 0.5 teaspoon of arrowroot powder, scraping up the browned bits from the bottom of the pan.
Simmer the gravy for 2 minutes until it reaches a thick, velvety consistency, then pour it over the chicken and serve immediately.