On a lightly floured work surface, roll out both discs of dough until about 1/8 inch (3 mm) thick. Line a 9-inch (23 cm) round, 2-inch (5 cm) deep glass or ceramic pie dish with one rolled out dough. Pour in the filling. Brush the edge of the dough with the beaten egg. Make a few incisions in the centre of the second rolled out dough and place over the pie. Remove any excess dough. Seal the dough together by pressing on the edge of the pie with your fingers. Brush the pie with the beaten egg.
