Boil potatoes and mash well.
Heat oil in a pan and sauté chopped onions. Next add chopped green chillies and capsicum. Then season with pepper, red chilli powder, salt and mix well.
Next add the canned tuna and once cooked, remove from flame.
Mix this with the mashed potatoes and make small patties.
Dip each patty first in egg white and then coat evenly with bread crumbs and fry in oil till golden brown.