Put some oil in a pan and sauté ginger, garlic till light golden. Then add capsicum, onion and carrots, fry it and remove from stove. In another pan; put stock, white pepper, tomatoes, brown sugar, ketchup, let it one boil. Then add corn flour mixture, till turn into thickness form. Add fried vegetables and prawns, cook few minutes. Lastly add green chilies, serve hot.