Crushed new potato fish cakes with horseradish mayonnaise

Try this new idea for fishcakes – they contain smoked haddock and hidden greens – then serve with a contrasting dipping sauce

Cook the potatoes in boiling salted water for 10-15 mins until tender. Drain in a colander over the spinach so the leaves wilt. Return the potatoes to the pan to steam-dry, then roughly crush with a fork. Leave to cool.
In a separate pan, poach the haddock in the milk with the bay leaves and peppercorns for 4 mins. Turn off the heat and leave to cook for a few mins more until the flesh flakes. Remove to a plate and break into large pieces, discarding the skin and any bones.
Mix the cooled potato, wilted spinach and haddock with the egg yolk and 3 tbsp of the poaching milk. Form into 4 chunky cakes and chill in the fridge, covered, for at least 30 mins, or overnight. Mix all the mayonnaise ingredients together and chill.
Heat the oil in a large pan over a medium heat. Sprinkle flour over the fish cakes and fry for about 5-6 mins on each side until golden and heated through. Serve with lemon wedges and a dollop of the horseradish mayo.