Begin by making the pastry. Sieve the plain flour into a large mixing bowl. Add in the pinch of salt.
Cut the butter into pieces and add this to the flour and salt. Using the tips of your fingers rub the butter into the flour until the mixture resembles fine breadcrumbs.
Add in the sugar at this stage also. Next mix in the water, gradually, until the mixture all comes together into a ball. Kneed lightly to achieve a smooth pastry and then wrap it in cling film and refrigerate for at least 1 hour but for longer if time will allow.
Preheat the oven to 170°C (325°F/Gas 3).
Roll the pastry out to line a quiche dish or a large tartlet plate. (Approx 9-10Inch)
In a separate bowl mix the sliced apples, sultanas, sugar and cinnamon together.
Pour this mixture into the centre of the tartlet and cover with another sheet of pastry.
Make up the egg wash glaze by mixing the egg and milk together.
Brush this over the top of the pie and if you have some scraps of pastry left over you can roll them into thin pieces of pastry and cut out some leaves.
Bake the pie for approximately 40-45 minutes until the pastry is golden brown and well cooked through to the centre.
When the pie comes out of the oven sprinkle with caster sugar and serve.