Custard pie with peaches (torta pasticciotta con le pesche)

Instructions

1. To make the pastry cream, place the milk and lemon peel in a medium–large saucepan over medium–low heat and gently bring to just below boiling point.
2. Meanwhile, place the egg yolks, sugar and cornflour in a large heatproof bowl and whisk until creamy. When the milk is almost boiling, remove it from the heat. Pour 3 tablespoons of hot milk into the egg mixture and stir vigorously with a wooden spoon. Pour in another 3 tablespoons of milk, mixing the whole time. (If you add too much hot milk at the beginning it will scramble the eggs, so take this part slowly.) Stirring constantly, gradually add the rest of the milk, which will have cooled by now so you can pour a bit more generously.
3. Return the custard to the saucepan and stir with a wooden spoon over low heat until it starts to thicken – this might take 10 minutes or so, but don’t stop stirring and scraping the bottom of the pan, smoothing any lumps with the back of the spoon. At this point you can remove the lemon peel with tongs. When the custard is thicker and noticeably more difficult to stir, remove it from the heat and pour it into a heatproof ceramic bowl. If you see a few lumps, pour it into a sieve and push the cream through with a scraper. Place plastic film directly on the surface of the cream (to stop a skin forming) and over the side of the bowl. Cool to room temperature, then chill in the fridge overnight.
4. To make the pastry, place the flour, sugar and salt in a large bowl and whisk to remove any lumps. Add half the butter and work it in with your fingertips, then add the remaining butter and work it in until the mixture resembles wet sand. If your work space is warm and the butter starts to melt, put the bowl in the fridge or freezer for a few minutes, then continue to work on it.
5. Whisk the egg and egg white together and add to the flour mixture, mixing with a wooden spoon initially and then with your hands to bring the dough together. Briefly knead the dough until smooth, then wrap it in plastic film and rest in the fridge for at least an hour (overnight is fine).
6. Preheat the oven to 180°C (350°F). Butter and flour a deep 24 cm (9½ in) round cake tin. Remove the pastry from the fridge and cut it into two portions – you need two-thirds of the dough for the base and side, and one third for the lid. Roll out the larger portion of dough between two sheets of plastic film to a thickness of 5–6 mm (¼ in), to form a circle large enough to line the base and side of the tin. It should hang slightly over the edge as you will need to fold it over the pastry lid later. Carefully lift the pastry into the prepared tin, using your fingers to gently flatten it onto the base and side. Place in the fridge to chill for 15 minutes if the pastry is becoming soft.
7. Remove the pastry cream from the fridge – it should now be quite firm. Spread half over the pastry, patting it down with the back of a spoon so it is even, then layer on the peach slices. Pour on the remaining pastry cream and smooth the surface. Chill in the fridge or freezer while you roll out the pastry lid.
8. Roll out the smaller piece of dough to a thickness of 5–6 mm (¼ in), making a circle that just covers the top of the torta. Place the pastry lid on the filling and fold over the pastry from the side of the tin to form a seal. Trim off any excess, then make a number of light incisions across the top of the lid to mark out 10–12 slices. I push my knife through the pastry along the incisions for about 3 mm (¹⁄8 in) closest to the edge of the lid to help any steam escape during baking. Brush the beaten egg yolk over the pie top.
9. Bake for 1 hour or until the pastry is cooked and golden, then let the pie cool completely before removing it from the tin. Dust with icing sugar before serving. Leftovers will keep, covered, in the fridge for up to 3 days.