Lightly salt the prawns and leave for 5 minutes. Rinse away the salt and dry the prawns on paper towels.
Mix the prawns with salt, Chinese cooking wine and egg white. Add 1 tablespoon cornflour, stir well and leave to marinate.
Beat the eggs and stir in the salt and white pepper. In a separate bowl, mix the cornflour and cold water to make the starch paste.
Bring a pot of water to the boil, add the prawns and cook till they just turn pink, about 30 seconds. Drain and add to the egg mixture. Add the spring onions and starch paste then mix well.
In a hot wok, heat 2 tablespoons of oil. Pour in the prawn mixture and let it set - do not stir until the edges are cooked. Stir fry quickly in a circular motion. As soon as the eggs are done, remove from the heat - do not overcook.
For best texture you need to stir-fry at a fast pace, so have everything mixed and ready before cooking.
Eggs absorb cold oil so make sure the oil is hot before add the egg mix.