Remove shells and intestines of prawns. Rub in 2 tbsp of cornstarch, rinse briefly, and soak up all moisture with a piece of kitchen paper. Mix with marinade and mix well.
Combine ingredients of seasonings.
Heat some oil, and shallow fry prawns until half done.
Heat some oil, fry scallion until fragrant, the add in washed peas and saute until done. Add in prawns and seasonings and stir quickly. Thicken with cornstarch solution if sauce is too watery, and serve immediately.