Haddock, prawn & crab pie

Put the potatoes in a large pan, cover with cold water, bring to the boil and simmer for 12-15 minutes until tender. Meanwhile, put the haddock in a large frying pan milk; bring to a boil, then immediately reduce the heat and simmer for 6-8 minutes until the fish is just cooked through. Transfer the fish to a plate and pour the milk into a jug.

Melt 50g butter in a saucepan, add the flour and cayenne, then cook for 2 minutes. Gradually beat in the infused milk, then bring to the boil and simmer gently for 2 minutes until thickened. Reduce the heat to low and stir in the spinach, in batches, until wilted. Meanwhile, boil the kettle, then put the peas in a colander and pour the just-boiled water over to defrost them. Drain well and add to prawns, mustard and ½ of the chives; stir to combine. Flake the haddock into large chunks, then carefully fold through the sauce, taking care not to break the fish up too much. Spoon into an ovenproof dish roughly 28x18cm.

Preheat the oven to 200°C, gas mark 6. Drain the potatoes well, then mash until smooth. Beat in the remaining 30g butter and milk, then stir through the remaining chives; season. Spoon the mashed potato over the filling and spread out evenly. Use the back of a spoon or fork to swirl patterns on the top. Put the pie onto a baking tray and bake for 25-30 minutes until the fish and prawns are cooked through and opaque, and the top is bubbling and golden.