Slice the chicken breast into even strips and submerge them in the low-fat buttermilk for at least 20 minutes to tenderize.
In a shallow dish, whisk together the whole wheat flour, garlic powder, onion powder, sea salt, and black pepper until well combined.
Remove each chicken strip from the buttermilk, allowing excess to drip off, then dredge thoroughly in the flour mixture, pressing to adhere.
Lightly coat the air fryer basket with avocado oil and arrange the chicken in a single layer without overcrowding.
Air fry at 400°F for 12-15 minutes, flipping halfway through, until the coating is golden brown and the internal temperature reaches 165°F.
While the chicken cooks, steam the green beans until they are vibrant and tender-crisp, and roast or microwave the sweet potato until soft.
Serve the crispy chicken strips immediately alongside the steamed green beans and the warm sweet potato.