Marinade the prawns in a mixing bowl with ground white pepper and salt.
Sift the tapioca flour and corn flour into a large bowl. Using a whisk, add water progressively and mix until the sifted flours develop a smooth batter.
Fill up a wok with one-third full of rice bran oil and heat over medium to high heat.
Dip each prawn in the beaten egg then into the batter, allow excess to drain off, and carefully drop in hot oil and deep-fry for 2 minutes or until lightly golden. Remove from wok and drain on kitchen paper towel. Repeat the same process in batches until all the prawns are cooked.
To serve, garnish with red chillies, spring onions and freshly grind black peppercorns.