The recipe
Scrub 400g of King Edward or other floury-fleshed baking potatoes then cut into large chunks and boil in deep salted water for 10-15 minutes or until tender enough to mash. Drain the potatoes and crush them with a potato masher or a fork, keeping the texture rough and lumpy. Finely shred 400g of leeks, then let them completely soften in 10g of butter over a moderate heat.
Cook 300g of smoked haddock in 250ml of milk together with a bay leaf and 6 black peppercorns. When the fish is opaque, remove and discard the skin, break the flesh into large flakes, then mix with the crushed potatoes and half the cooked leeks. Shape into 6 rough patties, then fry until crisp and golden in a little oil and butter and serve with the remaining leeks. Serves 6.
The trick
Cook the fish only until it is opaque. I often just bring the milk to the boil, turn off the heat, cover with a lid and leave for 10 minutes. All the cooking it needs.
The twist
Use another type of fish if you prefer. You could peel the potatoes before cooking them and mash them to a soft cream for a more classic result. Include a little cooked spinach, well drained and squeezed dry, in place of the leeks. Add a few capers. Make a hollandaise to accompany it.
Email Nigel at nigel.slater@observer.co.uk
"I often just bring the milk to the boil, turn off the heat, cover with a lid and leave for 10 minutes. All the cooking it needs...": Nigel Slater on making smoked haddock and leek fishcakes. Photograph: Jonathan Lovekin for the Observer