1. Marinate the Chicken: In a large mixing bowl, combine soy sauce, sesame oil, white pepper, sugar, and minced garlic. Add the chicken pieces and mix well to ensure each piece is thoroughly coated. Let it marinate for at least 30 minutes to infuse the flavors deeply.

2. Prepare the Coating: In another bowl, mix sweet potato starch, Chinese five-spice powder, and salt. After marination, dip each piece of chicken into the beaten egg, then dredge in the starch mixture until well coated. This double coating is key to achieving that signature crispiness.

3. Preheat Your Air Fryer: Set your air fryer to 180°C (350°F) and allow it to preheat for about 3 minutes. This step ensures a stable cooking temperature from the start.

4. Cook in Batches: Arrange chicken pieces in a single layer in the air fryer basket. Spray lightly with cooking oil to help achieve a golden color. Avoid overcrowding the basket; cook in batches if necessary.

5. Frying Time: Cook for 12 minutes, then use tongs to flip the chicken pieces. Spray lightly again with oil and cook for another 8 minutes or until the exterior is crispy and golden brown.

6. Check Doneness: Ensure each piece is cooked through. The chicken should reach an internal temperature of 74°C (165°F) when tested with a meat thermometer.