Mix all the ingredients of Marinade in a big bowl, stir well. Add the chicken pieces and marinate for 30 minutes.
Heat up the oil in the wok for deep-frying. Coat the chicken with the cornstarch evenly. Deep-fry the chicken until they turn golden brown, remove from the oil and set aside.
Pour the oil out and add the basil leaves and stir a few times before adding the chicken back into the wok. Remove from the wok, add the pepper salt and toss well with the chicken. Serve immediately.
Notes
Basil leaves are optional if you can't find them. You can find the bottled pepper salt at Asian grocery stores. It looks like this. Depending on the brands, the label can also be "white pepper and salt" or "white pepper salt."