Boil the potatoes and after cooling, peel the skin off and mash well.
On a separate bowl, take the mashed potato and fish meat. Mix well so that there are no crumbs.
On a separate bowl, add the sliced onions, chopped green chillies and coriander leaves. Mix well by adding the turmeric and coriander powders and salt.
On a pan heat add one tablespoon of the oil from the 2 cups of oil. Fry the sliced onions, chopped green chillies and spice mixture until the onions turn soft. Add the mixture to the mashed potatoes and mix well. After everything has been mashed and mixed well, make small balls of potato -spice mixture.
Pour the biscuit crumbs on a plate. Beat eggs in a separate bowl.
Heat oil in a deep frying pan. Dip the spiced potato ball in egg beat and wrap biscuit crumbs around it. Deep fry the ball until it turns brown.
Sprinkle crushed black pepper on the balls and serve with tomato ketchup or chutney.