Best-ever Fish Pie

Method

Make your pastry. Put the flour and salt in a mound on your work surface and scatter the butter, cubed, over the top. Use your rolling pin to roll the butter into the flour; keep going until it’s the texture of rolled oats. Then put into a pile with a well in the centre, add water and knead to make a rough dough.

Roll out or press the dough into a rectangle 2–3 cm thick. Fold one-third of the dough into the middle, then the other third over the top of that, as if folding a letter. Rotate the dough 90 degrees and roll it out again into a rectangle 2–3 cm , then repeat. Don’t worry about making these folds perfectly neat – this is just to finish layering the butter, which results in a lovely flakiness. Finally, wrap and refrigerate for at least 1 hour.

While the pastry is resting, make the filling. Shell the prawns and cut all the fish into 2–3 cm pieces, then put it all in the fridge. As you prepare your ingredients, set aside the prawn shells and vegetable trimmings, then use them to make a quick stock. Put it all in a saucepan and cover with 350 ml water. Bring to a gentle boil and simmer for 20 minutes, then remove from the heat to cool before straining.

Heat the olive oil in a large heavy-based saucepan over a low–medium heat. Add the fennel, shallot, leek and garlic and cook with the lid on, stirring occasionally, for about 10 minutes, or until softened but not browned. Transfer to a large bowl.

Return the pan to a medium heat and melt the butter. Add the flour and whisk to combine. Cook, whisking, for 4–5 minutes until the mixture darkens slightly. Add the fish stock, whisking if necessary to get rid of any lumps, then add the milk and bring to the boil. Reduce the heat to low and simmer for 2–3 minutes until the béchamel thickens. Set aside to cool.

Add the prawns, fish and béchamel to the fennel mixture. Add the chives, parsley, fennel fronds, lemon zest and juice, mustard, salt and pepper and stir to combine well. Transfer to a 23 cm square, 8 cm deep pie dish, or use a similarly sized oval or round dish. Refrigerate while you prepare your pastry. Put the pastry on a lightly floured kitchen bench and roll it out into a square roughly measuring 28 × 28 cm and 4 mm thick. Lay the pastry between two sheets of baking paper and refrigerate for 15-20 minutes.

Remove the pastry from the fridge and remove the top sheet of paper. Slide the pastry off the baking paper and on to the top of the pie dish, with the edges overhanging the side of the dish. To mark the top with ‘fish scales’, use a measuring spoon or melon baller to gently score semicircle indentations in a line along the top edge of the pastry, making sure that you don’t pierce the pastry. Follow this with another line directly underneath, offsetting the scales above. Continue all the way down the pastry sheet. Lightly brush the pastry with beaten egg, and use a knife to make a couple of steam holes in the top. Cover with baking paper and return it to the fridge to rest for another 30 minutes.

To bake the pie, preheat the oven to 180°C/Fan 160°C/Gas 4 . Bake for 40–45 minutes, turning the dish halfway through, until the pastry is flaky and golden.