Pre-heat the oven to 375º F (Gas Mark 5). For pastry, rub together the pea flour and fat until the mixture resembles fine breadcrumbs. Add the sugar. Mix the beaten egg and water together then add to the dry mixture. Mix to a dough. At this stage the pastry will be somewhat wetter than traditional shortcrust pastry. Do not allow the pastry to rest, but instead use immediately. Divide the dough into two uneven halves and use the larger piece to line an 8-9" pie dish. Add the fruit mixture and use the remaining pastry to cover the pie. Bake in the centre of the oven for about 25 minutes, until crisp and golden.

Crumble
Rub together the pea flour and fat until mixture resembles fine breadcrumbs. Add the sugar and mix well. Put the fruit in a lightly greased deep dish and cover with the crumble mixture. Bake as for the pie.

Note - the pastry is softer and more breakable than traditional shortcrust pastry and needs more gentle handling, especially when rolling out to large sizes. For the same reasons the pastry needs to be used much thicker than when using traditional pastries.