Grind Cumin, Coriander seeds, Clove, Cinnamon and Cardamom into coarse powder.
Boil and peel potatoes. Mash them into small pieces. Cut Onions,Green chilli, Coriander into small pieces.
Drain the Tuna of water. In a mixing bowl, add all the ingredients to Tuna chunks except bread crumbs and oil. Set aside in the refrigerator for 1/2 hour.
Divide the mixture into 10-12 rounds and flatten them into patties before rolling them in the bread crumbs.(You may freeze them at this point.)
Fry these in little oil in a flat skillet until they are browned on both sides. Serve them hot with ketchup.