Flake the fish carefully, making sure you've got rid of all of the bones.
Zest the lemon.
Place the fish, mayonnaise, chopped parsley and lemon zest in a large bowl and mix until you get the right consistency.
Season with salt and pepper.
Make 30-35g balls from the mixture.
Dip the fishcakes in flour, egg and breadcrumbs, in that order. Fry in roughly one inch of olive oil.