From "The Pie Room" by Calum Franklin
All credit to Calum Franklin for this take on the classic pie dish. We'll see how "Ultimate" it is.
Preheat the oven to 180 C fan/200 C/gas mark 6.
To make the potato topping, put the potatoes in a pan and add enough salted water just to cover them. Bring to the boil, then reduce the heat and simmer until the potatoes are very tender. Add the milk, double cream and butter to the pan and mash together with potatoes until smooth. Add the egg yolks with the table salt and mix until well incorporated.
Pour the milk and cream into a medium pan and bring to a simmer. Drop the diced fish and peeled prawns into the simmering milk and cream and poach for 2 minutes. Drain the fish, reserving the poaching liquid in a bowl.
Wipe out the pan and add the butter, bring it to a bubble over a medium heat and then whisk in the flour. Reduce the heat to low and cook for 8 minutes, whisking continuously. Add half of the reserved poaching liquid and bring back up to a simmer, whisking continuously to prevent any lumps from forming. Add the remaining poaching liquid and cook until thick and smooth. Add the peas, capers, chives, parsley, mustard, and table salt and mix well. Return the drained fish to the pan and lightly fold into the sauce, being careful not to break up the fish.
Spoon the pie mixture into a deep ovenproof dish and level the surface. Spread the mashed potato topping over the pie mixture, taking it right to the edges of the dish, and then ruffle the top with a fork to create texture. Scatter the grated cheese evenly over the surface of the pie.
Place the dish in the preheated oven and bake the pie for 30 minutes or until the sauce is bubbling up at the sides and the potato topping has a crispy golden crust
Servings 6