Place prawns, water, salt, white pepper, and oil in a blender or food processor and blend into a homogenous paste. Transfer to a large bowl.
¼ kg prawn- peeled and deveined, ⅓ cup water, 2 teaspoons salt, ¼ teaspoon white fine ground pepper, 1 teaspoon oil
Add the tapioca starch and mix to form a dough, it should not be too soft or sticky. You may have to add more water or tapioca flour. Knead several times until smooth.
2 cups tapioca starch
Roll the dough into a log, about 4 cm in diameter. Divide into two logs and roll to smoothen again.
Bring a pot of water to a boil over medium heat. Unwrap the dough and cook for 20-30 minutes turning it from time to time.
Transfer to a plate lined with parchment paper or greased lightly with oil and let it cool down completely. Refrigerate overnight to dry out for easy slicing.
Using a mandolin slicer, cut the dough into thin round slices. Place the slices on a rack and sun-dry for 6-12 hours or until totally dried out. You can also use your oven set to the lowest temperature (with fan is better) or a food dehydrator.
Heat about 2-3 inches of oil and fry the dried dough slices in hot oil for a few seconds after they float and remove from oil using a spider ladle.
Transfer to a colander to remove excess oil. Sprinkle some salt if needed and serve.