Remove the fat and cut the chicken into 1-inch chunks. Place in large bowl.
Make the marinade by adding all the ingredients to the bowl of chicken. Mix to coat all the chicken. Cover with plastic wrap and refrigerate for at least 30 minutes to overnight.
Once the chicken is done marinating, beat the egg with the 1/2 cup of water in a bowl. Place the sweet potato starch in another bowl.
Heat the frying oil until it reaches 350˚F.
While the oil is heating up, dip the chicken in the egg mixture first, then in the potato starch.
Once the oil reaches the right temperature, fry the Thai basil leaves for 30 seconds or until they darken.* This helps flavour the oil. Scoop them out and lay them on a wire rack or a plate lined with paper towels to drain off the excess oil.
Fry the chicken pieces for about 5 minutes or until golden brown. Make sure not to add too many pieces into the pot. Scoop them out and lay them with the leaves.
Immediately toss with generous amounts of salt, white pepper, cayenne pepper, and sugar, to taste.
*When frying Thai basil leaves, keep in mind of the big splash back due to the moisture in the leaves. I used a fryer and had a lid I quickly closed as I lowered the basket into the oil.