Cut chicken thighs into 2-inch pieces and place them in a mixing bowl. Combine the chicken with soy sauce, grated ginger, minced garlic, white pepper, Shaoxing wine, and egg white. Mix well to ensure all the pieces are evenly coated, then cover and let marinate in the refrigerator for at least 30 minutes, preferably overnight for deeper flavor penetration.

In a separate bowl, mix together five spice powder, additional white pepper, salt, and sugar. Pour coarse sweet potato flour onto a large plate. Retrieve the marinated chicken and dredge each piece in the flour, making sure to cover it completely.

Pour enough neutral oil, like avocado or peanut oil, into a deep frying pan to ensure the chicken pieces will be submerged. Heat the oil over medium-high heat until it reaches 350°F (175°C). Use a thermometer to check the temperature.

Carefully add the coated chicken pieces to the hot oil in small batches. Cook for 3-4 minutes, or until the chicken turns golden brown and crispy. Use a slotted spoon to transfer them to a wire rack lined with paper towels to drain excess oil.

In the last 30 seconds of frying the last batch of chicken, add fresh basil leaves to the hot oil. This quick fry will enhance the overall flavor.

Once all the chicken pieces are golden brown and crispy, remove them from the oil and drain on the paper towels. While still hot, sprinkle the chicken with your seasoning mix for added flavor. Serve immediately.