1 For the pastry: sift the flour into a mixing bowl and stir in the salt. Rub in the butter until the mixture resembles breadcrumbs. Gradually add water until the mixture just comes together. Roll the dough into a ball, then wrap in cling film and chill for 30 minutes.
2 Preheat the oven to 200°C (180° fan) 400°F gas 6. Grease a 1 l | 2 pint pie dish.
3 Roll out 2/3 of the pastry on a lightly floured surface and use to line the pie dish.
4 For the filling: mix together all the ingredients except the butter. Spoon into the pastry case and dot with butter.
5 Roll out the remaining pastry and cut into even strips.
6 Place the pastry strips on top of the filling to form a lattice.
7 Bake for about 30 minutes until the pastry is golden. Sift over a little icing sugar just before serving.