Pistachio streusel plum pie

Preheat the oven to 200oC, gas mark 6. Roll out the pastry on a lightly floured surface and cut out a 32cm circle. Use this to line a 25cm pie dish, then trim off any excess pastry and crimp the edges. Prick the base all over with a fork, line with baking parchment and fill with baking beans. Bake for 10 minutes; remove the baking parchment and beans and bake for a further 5-10 minutes, until golden and dry to the touch.

Meanwhile, in a bowl, combine the plums, cornflour, 60g sugar, the ginger and a pinch of salt; set aside. For the streusel, in another bowl, rub together the butter, flour and 25g sugar until the mixture resembles coarse breadcrumbs, then evenly mix through the pistachios. Tip the plums into the baked pie case and bake for 20 minutes. Sprinkle over the streusel and bake for a further 20-25 minutes until the topping is golden and the plums are soft. Let stand for 10 minutes before serving with ice cream, if liked.