Slice the chicken breast into even-sized cutlets or strips for uniform cooking.
Place the chicken in a shallow bowl and pour the buttermilk over it, ensuring every piece is coated, and marinate for 20 minutes.
In a separate wide dish, whisk together the arrowroot powder, garlic powder, onion powder, paprika, sea salt, and black pepper.
Remove each piece of chicken from the buttermilk, letting the excess drip off, then dredge thoroughly in the seasoned arrowroot mixture.
Heat the avocado oil in a large skillet over medium-high heat until shimmering.
Add the chicken to the skillet and sear for 4-5 minutes per side until the coating is golden-brown and the internal temperature reaches 165°F.
Remove the chicken from the skillet and set aside on a plate to rest.
In the same skillet, melt the ghee over medium heat, scraping up any browned bits from the pan.
Whisk 1 teaspoon of the remaining seasoned arrowroot into the cashew milk, then pour into the skillet with the fresh thyme.
Simmer the sauce for 2-3 minutes, whisking constantly, until the gravy reaches a velvety consistency.
Plate the crispy chicken and pour the warm herb gravy over the top before serving.