Ingredients

• 5-6 large baking potatoes
• 1 tbsp vegetable oil
• handful rock salt
• 200g/7oz mussels
• 150ml/5fl oz white wine
• 1 onion
• thinly sliced
• ½ tsp black peppercorns
• 2 bay leaves
• 500g/1lb 2oz boneless
• skinless smoked haddock
• 400g/14oz salmon
• bones and skin removed
• 400g/14oz cod
• bones and skin removed
• 200g/7oz butter
• 3 heaped tbsp plain flour
• 475ml/17fl oz milk
• 1 lemon
• zest and juice
• 4 tbsp chopped flat leaf parsley
• 250g/9oz cooked peeled prawns
• 1 cooked lobster
• meat removed
• 150g/5½oz strong cheddar
• grated
• 200g/7oz peas
• 50g/1¾ unsalted butter
• salt and pepper

Directions

• For the fish pie
• preheat the oven to 180C/160C Fan/Gas 4.
• Prick the potatoes all over with a fork
• then rub with a little oil. Sprinkle a roasting tray with the rock salt and place the potatoes on top. Bake for 1-1½ hours
• or until tender.
• Clean the mussels in running water. Discard any open mussels that do not close when given a sharp tap. Put a large saucepan over a high heat. Add the mussels and white wine
• cover with a lid and cook for 2-3 minutes
• or until the mussels have opened. Strain and discard any mussels that have not opened (keep the cooking liquor). Pick the mussels from their shells.
• Meanwhile
• half-fill a large frying pan with water and bring to a simmer. Add the onion
• black peppercorns
• bay leaves and all the fish. Poach for 3-4 minutes
• then lift the fish from the pan using a slotted spoon and set aside. Strain the fish stock through a sieve suspended over a large bowl. Reserve the strained stock and discard the onion
• bay leaves and peppercorns.
• Melt 100g/3½oz of the butter in a saucepan over a medium heat. Whisk in the flour to form a smooth paste
• then cook for a further 1-2 minutes.
• Whisk in 50ml/2fl oz of the milk until it is fully incorporated into the sauce. Continue to add 350ml/12fl oz of the remaining milk little by little
• whisking after each addition
• until the sauce is smooth and thick. Add 500ml/18fl oz of the fish stock and the cooking liquor from the mussels
• stir well and cook for 4-5 minutes
• or until the sauce is smooth and just thick enough to coat the back of a spoon. (Any remaining fish stock can be chilled and frozen for use in another dish.)
• Stir in the lemon zest
• juice and parsley
• then season with salt and pepper. Remove from the heat. Stir the prawns and lobster meat into the sauce
• then flake in the poached fish
• keeping it in fairly large pieces. Transfer the pie filling to a large ovenproof dish.
• When the potatoes are cooked
• remove them from the oven and increase the oven temperature to 220C/200C Fan/Gas 7.
• Slice the potatoes in half
• scoop out the flesh and pass it through a potato ricer into a pan set over a medium heat. Add 75g/2½oz of the butter and the remaining 75ml/2½fl oz milk to the potatoes and beat over the heat until the mash is smooth
• thick and not too soft.
• Spoon the mash into a piping bag with a large star-shaped nozzle and pipe the mashed potato all over the fish pie filling. (Alternatively
• just spread mashed potato over the filling.) Sprinkle over the grated cheese.
• Place the ovenproof dish onto a baking sheet and bake for 5-10 minutes
• or until the cheese and potatoes are golden-brown and the pie is heated through.
• Meanwhile
• bring a pan of salted water to the boil
• add the peas and cook for 2-3 minutes until tender. Drain well and return to the pan
• then stir in the butter and season with salt and pepper. Serve the fish pie with the peas alongside.