Place the apples in a pan with the water and sugar. Cook stirring gently until they are softened. Taste for sweetness and add more sugar if necessary. Leave to cool.
Divide the pastry into two portions. One slightly bigger than the other. Roll out the larger one for the base on a lightly floured surface and use to line a 24cm pie dish.
Spoon the cooked apples into the pastry shell, spread it to the edge and doming in the middle.
Roll out the remaining pastry.Brush the edges with a little milk and lay the rolled out pastry on top. Trim the edge and then crimp. Brush the pastry lid and then brush with milk and sprinkle with sugar.
Place on a baking tray and place in a preheated oven at 220°(200° fan oven Gas 7) Bake for 25-30 minutes until the pastry is golden. Serve with cream, custard or ice cream.