500g fresh large prawns, shells kept on
1 tsp salt
vegetable oil for deep frying
4 cloves garlic, chopped
1 thumb-length ginger, chopped
4 stalks spring onion, chopped
1 tsp cornflour
2 tbs light soya sauce
2 tsp sugar
1 tbs rice wine or dry sherry
1 tbs tomato ketchup
Wash prawns well and trim whiskers and legs. Pat dry with paper towels. Put into a large bowl, sprinkle with salt and mix well. Let stand for about 20 minutes.
Prepare the sauce in the meantime by mixing together cornflour, light soya sauce, sugar, sherry or wine and ketchup in a bowl. Leave aside.
Half fill a wok with oil. Heat till smoking hot or till a small piece of bread sizzles when tossed into the oil. The right temperature is important because you want to sear the prawns. Tip all the prawns into the oil, moving them gently with long chopsticks for about 1 minute.
Turn off the heat, remove prawns immediately using a slotted spoon and drain on paper towels.
Empty all but 2 or 3 tablespoons of oil in the wok. Reheat oil until smoking hot. Saute chopped garlic and ginger till fragrant, then return prawns to the wok. Pour sauce over, tossing prawns until most of the sauce has been absorbed. Add spring onion and serve immediately.