Prep the chicken thighs by cutting them into 1 or 1 1/2-inch thick pieces. Transfer to a medium mixing bowl. Add soy sauce, Shaoxing cooking wine, salt, sugar, Chinese five-spice powder, white pepper, and garlic. Mix until well combined. Cover with plastic wrap then set aside in the fridge to marinate for at least 1 hour.
While the chicken is marinating, prepare the Thai basil aioli. In a tall and narrow glass container, combine Thai basil, egg yolks, sambal, garlic, rice vinegar, salt, and neutral oil. Using an immersion blender, blend until thick and well blended. Pour in extra virgin olive oil and blend until just combined. Avoid over-blending otherwise, the aioli may become bitter. Cover with plastic wrap and place in the fridge until ready to use.*If you don't have an immersion blender, you can use a blender or food processor. Combine all ingredients except for the neutral oil and olive oil. Blend the ingredients then slowly drizzle in the neutral oil. Once the aioli has formed and is well combined, slowly drizzle in the olive oil until just combined. To prepare the white peppercorn seasoning, combine salt, sugar, white pepper, and Chinese five-spice powder. Set aside for later.
Preheat a deep pot over medium heat with 4 cups of neutral oil to 350F (175C). Place the tapioca starch into a large mixing bowl. Remove the chicken from the fridge.
Using your fingers, sprinkle 1 tsp of water into the tapioca starch then immediately stir. This will create small beads that will be coated over the chicken to create crunchy bits.
Dip each piece of chicken into the tapioca, making sure all sides are coated. Carefully place into the hot oil and fry for 2 to 3 minutes. Be sure to work in batches to avoid overcrowding the pot. Transfer to a wire rack or plate lined with paper towels. Repeat until all chicken has been fried.
To double fry, increase the heat to 400F (205C). Carefully place the chicken into the hot oil and fry for 1 to 2 minutes or until golden brown and crispy. Work in batches to prevent overcrowding. Transfer to a wire rack or plate line with paper towels. Immediately sprinkle the white peppercorn seasoning on top. Repeat for the rest of the chicken.
To assemble the baos, first have the steamed baos hot and ready! Take one bao and add 1 to 2 teaspoons of the Thai basil aioli to the bottom, making sure to spread it out evenly so the entire bottom layer of the bao is coated. Layer on 2 to 3 pieces of fried chicken. Add more Thai basil aioli on top of the chicken. Garnish with pickled red onions and cilantro. Serve and enjoy!
