Place the chicken breast in a small bowl and pour the buttermilk over it, ensuring it is fully submerged to marinate for at least 20 minutes.
In a shallow dish, whisk together the whole wheat flour, arrowroot powder, smoked paprika, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, allowing any excess to drip off, and dredge it thoroughly in the flour mixture until evenly coated.
Heat the avocado oil in a medium skillet over medium heat until it begins to shimmer.
Carefully place the chicken in the skillet and cook for 6 to 7 minutes per side until the crust is golden brown and the internal temperature reaches 165 degrees Fahrenheit.
Transfer the cooked chicken to a plate and let it rest while you prepare the gravy.
In the same skillet, add the chicken bone broth and fresh thyme, using a whisk to scrape up the flavorful browned bits from the bottom of the pan.
Simmer the broth over medium-high heat for 3 to 5 minutes until it reduces into a thick, creamy consistency, then pour the gravy over the chicken and serve immediately.