Place the chicken breast in a shallow bowl and pour the buttermilk over it, letting it marinate for at least 15 minutes to tenderize.
In a separate small bowl, whisk together the whole wheat flour, smoked paprika, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting excess liquid drip off, then dredge thoroughly in the flour mixture until evenly coated.
Heat the avocado oil in a medium skillet over medium-high heat until shimmering.
Add the chicken to the skillet and cook for 5-6 minutes per side until the crust is golden brown and the internal temperature reaches 165°F.
Remove the chicken from the pan and set aside on a plate; lower the skillet heat to medium.
Whisk the arrowroot powder into the milk until completely dissolved, then pour the mixture into the hot skillet.
Whisk constantly, scraping up any browned bits from the bottom of the pan, and simmer for 2 minutes until the gravy is thickened.
Stir in the fresh parsley and pour the warm gravy over the chicken before serving.