Make a paste with coriander leaves, mint leaves, black pepper, clove, green chilies, cinnamon and Ginger garlic paste. Add water as little as required. Add salt, corn starch powder and citric acid and mix well. Marinate the fish pieces in the paste. Cover and keep aside for 30 minutes or more. Pan fry around 4-5 minutes on each side or until crunchy on both sides. Serve with onions and lemon.