Place the chicken breast in a shallow bowl and pour the buttermilk over it, ensuring it is fully submerged; marinate for at least 30 minutes in the refrigerator.
In a separate shallow dish, whisk together the arrowroot powder, sea salt, black pepper, garlic powder, onion powder, and paprika.
Remove the chicken from the buttermilk, letting the excess drip off, then dredge it thoroughly in the arrowroot mixture until evenly coated.
Heat the avocado oil in a medium skillet over medium-high heat until shimmering.
Carefully place the chicken in the skillet and cook for 5-6 minutes per side, or until the exterior is golden-brown and the internal temperature reaches 165 degrees Fahrenheit.
Remove the chicken from the pan and set aside to rest on a plate.
In the same skillet with the remaining drippings, whisk in the whole wheat flour for 1 minute, then slowly pour in the almond milk while whisking constantly.
Simmer the gravy for 2-3 minutes until thickened and smooth, then pour over the chicken and serve immediately.