Fishcakes are a great way to use up leftover mashed potato. Serve with tartare sauce and a simple salad.
Heat the oven to 190C/375F/Gas 5.
Put the fish in a roasting tin and cook in the oven for about 10-15 minutes until opaque and starting to flake. When cool enough to handle, take off the skin, remove any bones and flake the fish into large chunks.
Mix the fish, mashed potato, parsley and egg together until well combined. (Mix together carefully so as not to break up the fish too much.) Season, to taste, with salt and freshly ground black pepper.
Shape the mixture into 8-12 patties, depending on how large you want them to be and set aside to chill in the fridge for one hour.
Heat some vegetable oil in a frying pan and heat the fish cakes until golden brown on each side and heated right through.
Serve with tomato sauce, parsley sauce or hollandaise sauce.