Place the chicken breast between two sheets of parchment paper and pound to an even half-inch thickness.
Submerge the chicken in buttermilk in a shallow bowl and let marinate for at least 15 minutes.
In a separate shallow dish, whisk together the whole wheat flour, garlic powder, onion powder, paprika, sea salt, and black pepper.
Remove the chicken from the buttermilk, allowing the excess to drip off, and dredge thoroughly in the seasoned flour mixture.
Heat avocado oil in a medium skillet over medium-high heat until shimmering.
Place the chicken in 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 to rest; meanwhile, whisk the almond milk and arrowroot powder together in a small bowl.
Pour the milk mixture into the hot skillet, scraping up the browned bits from the bottom, and whisk constantly until the gravy thickens.
Drizzle the creamy gravy over the chicken and garnish with chopped fresh parsley before serving.