Cut the fish into cubes.
Prepare a paste using the marination ingredients and marinate the fish for 1 hour.
Heat oil in a deep pan. Deep fry the fish and keep it aside.
Take some oil in a pan and add 3 small finely chopped onions and fry till the onions turn light brown.
Add finely chopped green chilli, chopped capsicum, garlic cloves, ginger, all finely chopped. Add tomato sauce, soy sauce, red chilly sauce and green chilly sauce.
Add cornflour mixed in water and add it to the pan and bring it to a boil.
When the gravy thickens, add fried fish pieces and fry for 2-3 minutes
Garnish with coriander leaves.