Preheat the oven to 200°C.
Sieve the flour and salt into a mixing bowl.
Rub in the fat until the mixture looks like fine breadcrumbs.
Mix in cold water with a knife and firm the dough with your hands.
Roll out half the pastry to cover a 20cm plate and trim the edges.
Spread the stewed apples over the base and sprinkle with sugar.
Roll out the remaining pastry and place it over the moistened bottom edges.
Press the edges to seal and trim away any excess dough.
Flute the edges of the pastry using your fingers and thumb.
Prick the surface and bake for 20 to 30 minutes.
Check that the pie moves slightly on the plate when shaken.
Transfer to a serving plate and dust with caster sugar.