In a mixing bowl, combine prawn paste (shrimp sauce), sugar, sesame oil, wine, and pepper.
Add chicken pieces and mix till well coated with marinade.
In a separate bowl, mix all the batter ingredients, and stir with a spoon or whisk, until smooth and free of lumps.
Add this to the chicken in marinade, and stir until well combined.
Cover with cling wrap, and set aside (refrigerated) for at least 8 hours, preferably overnight, or up to 2 days.
Fill a wok or skillet with cooking oil to a depth of 1 - 1 1/2 inches. Heat oil to 175 - 180 deg C.
Fry the chicken pieces in batches, about 4 to 5 at a time (it's a good idea to fry like pieces together). After about half a minute, separate the pieces with wooden chopsticks, to prevent pieces sticking together.
After about 1 minute, the temperature should have dropped to 160 deg C, if not lower the heat. Cook for about 4 to 5 minutes, or until deep golden brown.
Scoop out with a slotted spoon and drain on a metal rack. Allow the oil to get hot again, before adding the next batch. Repeat until all pieces have been fried.
Serve immediately, with freshly squeezed lime juice and sweet chilli sauce on the side (optional).