Oyster and seafood pie with samphire

Method

1. Preheat the oven to 220°C.
2. Put 75g of the butter into a saucepan and heat until melted, then add the flour and cook for 2 minutes until thickened and light golden-brown.
3. Add the cream gradually, whisking all the time, and cook until thickened and smooth. Pour the champagne in a steady stream into the sauce, still whisking all the time, until thick enough to coat the back of a spoon, then season to taste with salt and pepper.
4. Place the salmon, smoked haddock, lobster, oysters, prawns and samphire in a large ovenproof dish. Pour the sauce over the top to coat everything.
5. Put the grated potato into a clean tea towel and squeeze all the liquid from it. Place in a bowl. Melt 50g of the remaining butter in a saucepan, then mix with the potato and egg yolks and plenty of salt and black pepper.
6. Sprinkle over the top of the fish, then place on a baking sheet in the oven and bake for 30 minutes until golden and hot through.
7. Bring a pan of salted water to the boil, add the peas and cook for 2–3 minutes until tender. Drain and return to the pan, add the remaining butter and season to taste. Serve with the fish pie.