Place the chicken breast between two sheets of parchment paper and pound to an even half-inch thickness.
Submerge the chicken in the buttermilk in a shallow bowl and marinate for at least 15 minutes.
In a separate wide bowl, whisk together almond flour, arrowroot, smoked paprika, garlic powder, onion powder, sea salt, and black pepper.
Remove the chicken from the buttermilk, letting excess drip off, then dredge in the flour mixture, pressing firmly to ensure a thick, even coating.
Heat the avocado oil in a cast-iron skillet over medium-high heat until the oil is shimmering.
Carefully place the chicken in the pan and cook for 4-5 minutes per side until the crust is deeply golden and the internal temperature reaches 165°F.
While the chicken cooks, toss the shredded cabbage with apple cider vinegar and a pinch of salt to create a bright, acidic slaw.
Serve the crispy chicken immediately alongside the fresh slaw for a balanced, clean-eating feast.