Home-made fishcakes are a wonderful way to use up leftover mashed potato or fish (but don't worry if you don't have any leftovers - you can make your own). And they are so much better than the vaguely fish-flavoured mush covered in breadcrumbs that probably spilled out of your freezer when you were a kid.
Prep the Potatoes and Fish
Peel the potatoes and chop them into evenly-sized chunks. Place in a pan of boiling salted water and simmer for about 20 minutes, until tender. Drain and mash the potatoes with a knob of butter, a splash of milk (try not to add too much liquid), a pinch of salt and a teaspoon of mustard if liked. Place in the fridge to cool completely.
Put the fish fillets in a frying pan with enough milk to cover them. Add the dill and simmer until the fish flakes easily. Remove fish from the milk and allow to cool. Keep the milk for the sauce.
Make the Parsley Sauce
Melt a knob of butter in a small saucepan. Stir in the flour to make a smooth paste. Stir in the milk that the fish was cooked in. Add more milk if the sauce is too thick. Stir in the chopped parsley and salt to taste. Simmer for 2 minutes, then remove from the heat until needed.
Assemble the Fishcakes
Fold the fish flakes into the mashed potato. Divide the mixture into four, shape into flat discs about 2cm (1 inch) thick and lightly coat both side and the edge with flour. Pour the beaten egg onto a small plate and dip each fishcake in, coating it all over. Pour the breadcrumbs onto a plate and coat each fishcake with them.
Heat a generous quantity (it should be about 10mm/half an inch deep) of oil in a big frying pan, on medium heat. Gently lower the fishcakes into the pan and cook for about 6-7 minutes each side, until golden. Don't mess about with the fishcakes in the pan - just nudge them gently from time to time to make sure they don't stick.
To Serve the Fishcakes
Reheat the parsley sauce. Place 2 fishcakes on a plate with some garden peas. Pour the sauce over the fishcakes.