Marinate the prawns with turmeric powder, salt, lemon juice, rice flour and set it aside for half an hour.
Heat one tablespoon oil in a non-stick pan. Add prawns and stir fry till they turn pink in color or gets almost cooked.Heat remaining oil in another pan. Add ginger paste, green chillies and saute for a minute.
Add onions and saute tillit turns brown in color. Add green capsicum and saute for two minutes. Add prawns, black pepper powder and salt and mix well and cook for a minute.Serve hot with chopped coriander leaves.