Soak the rice in water for 2 hours.
Crush the coconut and onion separately in a mixer grinder.
Grind the soaked rice, crushed coconut and onion together in a grinder.
Put some fennel into it. Putting of turmeric powder is optional.
Make chili powder, salt and little water to make a paste. Apply the paste well on the mackerel.
Take a pan. Pour some oil and fry the mackerel.
Cut the mackerel into slight big pieces and remove the thorns of them.
Grind the coconut, fennel seeds, and chili powder and turmeric powder in a mixer grinder with little water as if to form a paste.
Put the chilly, ginger and garlic into the paste and crush them.
Take a pan and add some oil. Add curry leaves to it.
Put chopped onion into it. Sauté them well till it becomes brown color.
Add chopped tomato to it and sauté them well.
Add the coconut paste to it.
Cook them well. Put coriander leaves and off the stove.
Take a banana leaf. Apply little oil. Make a ball of the rice mixture and flatten the ball as if for a pathiri.
Put some masala over it.
Put one piece fried mackerel over it..
Fold the banana leaf.
Continue this process for every pathiri.
Steam these pathirees for some time.
Remove the banana leaf, cut them and serve hot.