Slice the chicken breast into even strips or nuggets to ensure uniform cooking.
Place the chicken in a small bowl with the buttermilk, ensuring each piece is fully submerged, and marinate for at least 20 minutes.
In a separate shallow dish, whisk together the almond flour, arrowroot starch, garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Remove each piece of chicken from the buttermilk, letting the excess liquid drip off, then dredge thoroughly in the flour mixture, pressing firmly to adhere.
Lightly coat the breaded chicken pieces with the avocado oil using a kitchen mister or brush.
Place the chicken in the air fryer basket at 400°F and cook for 12-15 minutes, flipping halfway through, until the exterior is golden and crispy.
While the chicken cooks, steam the broccoli florets for 5 minutes until they are vibrant green and tender-crisp, then serve immediately alongside the chicken.