Very loosely wrap the fish in tin foil and place on a baking tray in a pre-heated oven to 180℃, Gas Mark 4, for 12 minutes to cook it until it is easy to flake
Cook the potatoes and mash them using lots of butter, salt and pepper
Put the spring onions, parsley, egg yolk, English mustard and the mash into a mixing bowl. Zest the lemon and add the zest along with ½ tablespoon of juice to the mixture and mix well
Flake the cooked fish into the bowl and then carefully fold it into the mixture
Divide the mixture into patties at a size that suits you, place them on a baking tray lined with baking parchment and put them in the fridge for 20 minutes
After 20 minutes, take the fish cakes out of the fridge, dip them into the flour, shake off any excess then dip them into the beaten egg and, finally, the breadcrumbs
Heat some flavourless oil in a frying pan (we use rapeseed or sunflower) and fry the fish cakes for 3-4 minutes on each side until nicely golden brown. Serve with a nice crisp glass of white wine!