Instructions

To Make the Pastry

1. Place the butter, flour and icing sugar (powdered sugar) into the bowl of an electric stand mixer.
2. Using the paddle attachment, mix until everything looks crumbly or like wet sand.
3. Alternatively, you can do this in a food processor, or by simply rubbing the butter into the flour and sugar with your fingertips.
4. In a small bowl or cup, gently whisk together the egg and water.
5. Add the egg mixture slowly to the dry ingredients.
6. Mix until everything just comes together. You may not need all of the egg mixture.
7. Do not knead the dough.
8. Push the mixture together into a ball.
9. Wrap the dough in some plastic wrap.
10. Chill the dough in the fridge for at least 30 minutes.

To Make the Lattice Pie Crust

1. Separate the dough into two balls. One ball will be used to line the tart tin, whilst the other ball will be used to make the lattice pie crust.
2. Roll out one ball of dough into a circle and about 5mm thick. I recommend rolling the dough between two sheets of baking paper or plastic wrap as this will make it easier to transfer the dough to the pie dish.
3. Line the pie dish with your pastry.
4. Fill any holes in the pastry with some leftover dough, and prick the base with a fork.
5. Fill the pastry-lined tin with your pie filling. The pie filling should be either cold or at room temperature.
6. Roll out the second ball of dough into a circle and about 5 mm thick.
7. Cut an even number of strips of pastry of the same width. Use a sharp knife, straight pastry cutter, or pizzer cutter, to cut the strips of pastry. For best results, use a ruler to ensure that your strips are the same size.
8. Place half of the strips on top of the pie, evenly spaced apart.
9. Fold back every second strip of pastry onto itself, a bit more than halfway across the pie.
10. Place a strip of pastry perpendicular to the remaining strips on the pie. If you are making a pie with an odd number of strips in each direction (like that pictured), the first perpendicular strip of pastry should be in the middle of the pie.
11. Unfold the folded strips of pastry across the perpendicular strip of pastry.
12. Next, fold back the other strips of pastry, i.e. the strips which have not been folded back yet.
13. Place another strip of pastry perpendicular to the original strips of pastry.
14. Repeat this pattern with the remaining strips of pastry.
15. Trim the edges of the pie.
16. Chill the prepared pie in the fridge for at least 30 minutes before baking.

To Bake the Pie

1. Preheat the oven to 175°C/350°F (without fan).
2. Place a metal baking tray in the middle of the oven.
3. Brush the pie with some egg wash. 
4. If using, sprinkle the pie with some granulated sugar or demerera sugar.
5. Place the prepared pie onto the pre-heated metal baking tray.
6. Bake for about 35 minutes, or until the pie is lightly golden.