Place the chicken breast between two sheets of parchment paper and pound to an even half-inch thickness.
Place the chicken in a shallow bowl and pour the buttermilk over it, ensuring it is fully coated, and let it marinate for 15 minutes.
In a separate small bowl, whisk together the whole wheat flour, sea salt, black pepper, garlic powder, and onion powder.
Remove the chicken from the buttermilk, letting the excess drip off, then dredge it through the seasoned flour mixture until evenly coated.
Heat the avocado oil in a non-stick skillet over medium-high heat. Once hot, add the chicken and cook for 5-6 minutes per side until the crust is golden and the internal temperature reaches 165 degrees Fahrenheit.
Remove the chicken from the pan and set aside to rest. In the same pan, whisk the arrowroot powder into the almond milk until smooth.
Pour the milk mixture into the skillet, scraping up any browned bits from the bottom. Stir in the dried thyme and simmer for 2-3 minutes until the gravy has thickened.
Pour the warm gravy over the crispy chicken and serve immediately.