Cut the thighs into bite-sized pieces, roughly 3cm x 3cm (1" x 1").
Marinate them in the five spice powder, chicken bouillon powder, salt, sugar, grated ginger, finely chopped garlic, onion powder, corn starch, egg white, Shaoxing wine, light soy sauce, pepper and mashed fermented tofu for at least 20 minutes.
Toast the white and Sichuan peppercorns on low-medium heat until slightly brown, then use a sieve to sift out any unwanted particles.
Use a food processor to grind the peppercorns into a powder. Alternatively, use a pestle and mortar to crush them to achieve the same result.
Combine the ground peppercorns with the five spice powder, paprika and salt.
Mix the corn starch and baking powder together, then coat the cut pieces in the corn starch mix. Use a colander to shake away any excess starch.Tip: Put a few pieces in at a time so they are well-coated. Dumping many in will run the risk of a wet batter.
Heat up a wok of oil on medium heat and fry the coated pieces for 5 minutes or until golden.
Remove the pieces and let it drip dry in a sieve. Turn the heat up to high and double fry them for another 2 minutes.
Just before the chicken is ready, toss in the Thai basil leaves and let them fry for 2 minutes or until crispy. Scoop the chicken and leaves out into a large sieve or colander.
Put a serving of Taiwanese Popcorn Chicken into a large bowl along with some Thai basil. Add some of the spice mix in and toss all together until the batter is evenly coated.
Serve immediately as is!