Toss the chicken with the soy sauce, Shaoxing wine, and egg white. Let it sit 10 minutes while you chop the aromatics.
Stir the salt, white pepper, and sugar together in a small bowl. This is the seasoning that makes the dish, so do not skip mixing it in advance.
Add the cornstarch to the chicken and toss until each piece has a thin, slightly wet coating. Spray the air fryer basket with oil, lay the chicken in a single layer, and spray the tops.
Air fry at 200C (400F) for 12 to 14 minutes, shaking the basket once halfway, until golden and crisp at the edges. Cook in two batches if your basket is small.
In the last few minutes, heat the oil in a wok or large skillet over high heat. Fry the garlic until it just turns gold, then add the chilies and scallions for 30 seconds.
Add the hot chicken to the pan, sprinkle the salt and pepper mix over everything, and toss for 30 seconds so each piece picks up garlic and seasoning. Serve immediately.