Mix together plain flour, corn flour, crushed pepper (1 tbsp), egg white and salt, with a little water and make a thick paste. Marinate the prawns in this paste for 20 minutes.
Fry the prawns and keep it aside. In the same oil saute ginger,garlic & chopped onion. When the onion becomes soft add capsicum & spring onion. Saute for 5 minutes & add chilli powder & crushed pepper. Mix well.
Add the sauces & salt. Stir for a few minutes and add the fried prawns. Mix well.Cook for some more minutes till it becomes dry. Garnish with spring onion.