Cut the chicken thighs into 1 1/2 inch thick pieces.
In a bowl, combine the chicken thighs, grated garlic, soy sauce, Shaoxing cooking wine, orange juice, sugar, Chinese five spice powder, white pepper, and 1 teaspoon of salt. Mix well and marinate for at least 1 hour or overnight.
Heat a small skillet over medium heat and combine Sichuan peppercorns and white peppercorns (if using whole). Toast for 2 to 3 minutes, making sure to constantly stir to prevent the spices from burning. Remove and transfer to a spice grinder or mortar and pestle. Grind into a powder or your desired coarseness. Transfer to a bowl with 1 teaspoon of salt and 1 teaspoon sugar. Mix then set aside for later.
Fill a pot with neutral oil about half way up. Heat over medium heat to 350F or 175C.
Toss the chicken along with any juices in the bowl with tapioca flour. Add about 1 teaspoon of water to form small beads around the chicken.
For the first fry, carefully place the battered chicken into the hot oil and fry for about 2 minutes, or until golden brown. Be sure to work in batches to avoid overcrowding the pot. Transfer the fried chicken to a wire rack or plate lined with paper towel. Repeat until all chicken is fried.
For the second fry, raise the oil temperature to 400F or 205C. Working in batches again, carefully place the fried chicken into the oil and fry for 1 minute until golden brown and crispy. Remove immediately then sprinkle the Sichuan-white peppercorn seasoning over the chicken. Repeat for remaining chicken.
Pat the Thai basil leaves completely dry before adding into the hot oil. Carefully add the Thai basil and fry for 1 to 2 minutes or until they're crispy. Be sure to have a lid or splatter screen ready because the Thai basil will cause the oil the splatter vigorously! Remove then serve with the fried chicken. Sprinkle a little more Sichuan-white peppercorn seasoning on top and enjoy!
