Who doesn’t love cherry pie? Making the lattice on top of the pie can be fiddly – if you’re a beginner, try weaving your pastry strips on a piece of baking paper on a baking sheet, then sliding the entire lattice top onto your pie in one piece, positioning it as you go.
Make the pastry. Sift the flour into a bowl, then add the cubed butter. Using your fingertips, rub the butter into the flour, until the mixture resembles fine breadcrumbs. Stir in the icing sugar.
Whisk the egg yolk, 3 tablespoons of ice-cold water and the vanilla together in a bowl, then drizzle the egg mixture over the flour mixture. Mix with a table knife or small palette knife until the dough starts to come together. Add more water, 1 teaspoon at a time, if the dough feels dry.
Tip out the dough onto a lightly floured work surface and knead it until smooth. Divide the dough into 2 unequal pieces of one third and two thirds. Roll out the larger piece of dough on one of the lightly floured baking sheets to a 25cm-diameter circle. Chill for 15 minutes.
Roll out the smaller piece of dough on the remaining floured baking sheet to a 20cm square. Chill for 15 minutes.
Heat the oven to 220°C/200°C fan/425°F/Gas 7. Place a baking sheet on the middle shelf to heat up with the oven.
Make the filling. Mix the drained cherries, cornflour and sugar in a bowl, then stir in the cherry jam. Cut the butter into tiny pieces and set aside.
Use the chilled circle of pastry to line the tart tin, pressing it around the base and into the grooves. Trim the edges. Pour the cherry filling into the pastry case and dot with the pieces of butter.
Cut the remaining square of pastry into ten 2cm-wide strips. Brush the pastry strips with the reserved egg white, then brush the edge of the pastry in the tin with egg white.
Lay the pastry strips in a lattice over the cherry filling: lay 5 strips going in one direction then weave the other 5 in and out at right angles (in the other direction), leaving the loose ends of the strips hanging over the edge of the tin.
Once the lattice is in place, use the tin edge to cut off the strips by pressing down with your thumb, creating a neat finish. Sprinkle the preserving sugar over the pastry lattice.
Bake the tart on the pre-heated baking tray for 15 minutes, until the pastry has started to colour, then reduce the oven temperature to 180°C/160°C fan/350°F/Gas 4 and bake for a further 25–30 minutes, until the pastry is golden-brown and the filling set. Check on the pie from time to time – if the lattice seems to be getting too dark, cover with foil. Remove the pie from the oven and leave to firm up in the tin before removing to a serving plate. Dust with icing sugar, if you wish.
Make the custard. Heat the milk in a heavy-based pan over a medium heat to just below boiling point. In a bowl, whisk together the egg yolks, caster sugar, cornflour and vanilla extract until pale and fluffy. Pour the warmed milk over the egg mixture, whisking continuously, then return the mixture to the pan and cook over a very low heat for 3–4 minutes, stirring continuously, until smooth and thick enough to coat the back of a spoon. Remove from the heat and pour into a serving jug to serve alongside the pie.