Shell prawns but keep the tail intact, devein and wash thoroughly. In a bowl mix salt, half teaspoon black pepper powder, half of the crushed black peppercorns, two tablespoons of cornflour, one tablespoon of soy sauce.
Add the prawns, mix well and marinate for fifteen minutes. Dissolve one tablespoon cornflour in three tablespoons of water. Heat sufficient oil in a wok and deep fry the prawns for two minutes and drain on absorbent paper.
In a pan heat two tablespoons of oil. Add garlic, ginger, spring onions and sauté for two minutes on high heat. Add the prawns, salt, remaining black pepper powder, half of the remaining crushed black peppercorns, soy sauce, MSG, dissolved cornflour and spring onion greens.
Mix well. Stir fry on high heat for four minutes or until the prawns are cooked through. Before serving sprinkle the remaining crushed black peppercorns.