In a mixing bowl, combine 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 clingwrap, and set aside (refrigerated) for at least 8 hours, preferably overnight, or up to 2 days.
Fill a wok or frying pot (with a wide surface area), one-third full with cooking oil. Heat oil to 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 minutes, or until golden brown. Scoop out with a slotted spoon, and drain on paper towels. Repeat, until all pieces have been fried. Serve immediately, with freshly squeezed lime or calamansi juice, and sweet chilli sauce, on the side (optional).