1. If frozen prawns are used, defrost thoroughly. Devein the prawns and cut into 2cm pieces. Pat dry with kitchen paper. Put into a bowl.
2. Prepare the marinade: mix together the salt, cornflour and egg white. Stir into the prawns, making sure they are evenly coated. Refrigerate, covered, for a minimum of 3 hours or overnight.
3. Heat a wok over a high heat until smoke rises. Add 2 tbsp of the oil and swirl it around. Add the garlic and, as soon as it takes on colour, tip on the prawns. Separate them, stirring and tossing with a wok scoop or metal spatula for about 30-45 seconds or until almost cooked and turning pinkish. Splash in the wine or sherry around the side of the wok; as soon as the sizzling dies down, remove the prawns and put aside. Wash and dry the wok.
4. Beat the eggs lightly with 1 tbsp of the oil and a little salt. Heat a large frying pan until moderately hot, add 1 tbsp of the oil and swirl it around to cover the whole surface.
5. Pour in half of the beaten egg and tip the pan to spread the egg evenly to the edges. When firm, turn the crepe over and fry the other side for a few seconds. Remove the crepe to a plate and slice into thin strips.
6. Separate the rice grains as much as possible. Blanch the petits pois or peas in boiling salted water for 3 minutes and drain well.
7. Reheat the wok and over a high heat until smoke rises. Add the remaining oil and swirl it around. Stir in the white spring onion. Pour in the remaining beaten egg, then immediately tip in all the rice. Sliding the wok scoop or spatula to the bottom of the wok where the runny egg is, turn and toss the rice, separating any lumps.
8. When thoroughly hot, add the ham, stir, then the petits pois or peas, stir, and then the prawns. Still strring, add the soy sauce and stock.
9. Finally, put in half of the egg strips and the green spring onion. Remove to a warm serving platter and arrange the remaining egg strips on top for garnish.