Marinate the chicken with the soy sauce, rice wine, garlic, five-spice and 1/4 teaspoon white pepper for 30 minutes in the refrigerator.
Pour the sweet-potato starch into a shallow pan and press every piece of chicken into it until heavily pebbled.
Rest the coated chicken for 10 minutes while heating the oil to 350°F.
Fry one-third of the chicken for 3 to 4 minutes, stirring once, until crisp and 165°F in the largest piece.
Drain the batch on a rack and bring the oil back to 350°F before adding more chicken.
Mix the salt with the remaining white pepper and dust it over the hot finished chicken.
Rest for 3 minutes and serve while the starch shell is still brittle.