Slice the chicken breast into even strips.
Place chicken in a bowl and pour buttermilk over it, letting it marinate for at least 20 minutes.
In a separate shallow dish, whisk together the flour, garlic powder, onion powder, smoked paprika, sea salt, and black pepper.
Remove each chicken strip from the buttermilk, letting excess drip off, then dredge thoroughly in the seasoned flour mixture.
Preheat the air fryer to 400°F and lightly coat the basket with avocado oil.
Place the chicken in the basket and spray the tops with the remaining avocado oil.
Air fry for 12-15 minutes, flipping halfway through, until the coating is golden and the internal temperature reaches 165°F.
While the chicken cooks, steam the broccoli florets until tender-crisp.
Serve the crispy chicken immediately alongside the steamed broccoli.