Drain the tuna and place in a bowl using the fork to separate the chunks. Mix together with the water chesnuts, spring onions, ginger, coriander, chilli and limes leaves. Add fish sauce and beaten eggs and mix together.
With your hands, squeeze the mixture to compress it and get rid of any extra liquid before shaping it into balls the size of golf balls. Flatten them lightly into patties.
Heat a frying pan over a medium heat and fry the fishcakes on each side for 1-2 minutes until golden brown and warmed through. Serve with a dipping sauce of choice and salad.