Open the 7 oz can of tuna and drain out all the water. Use a strainer to drain out as much as you can. Spoon into a medium-sized bowl.
Now add the boiled and mashed potatoes along with the onions, chopped cilantro, green chilies, and spice powders. Mix well together, ensuring there are no lumps and all the ingredients are well blended. If you prefer to use a food processor, then you can put the ingredients into it and pulse a few times till coarsely blended.
Divide the mixture into eight portions. Form into tight balls and then flatten into round, compact cutlets. Refrigerate for 10-15minutes.
Break the egg into a wide bowl, add a dash of pepper and salt. You can also add a dash of chili powder if you like it spicier.
Beat lightly until the yolks are blended. Set aside near your cooking area.
Now, heat the oil in a large, deep frying pan.
Dip the cutlets in the eggwash, drain excess wash back into the bowl, and shallow fry 3 minutes on each side till nice and golden.
Serve with mint, coriander chutney, or ketchup. The cutlets can be used as snacks, or for lunch or dinner.