1. Preheat oven to 160C (140C fan-forced). Toss the apples and rhubarb with sugar and lemon juice in a non-reactive ovenproof dish, loosely cover and bake for 40 to 50 minutes, or until tender. Remove from the oven and set aside to cool.

2. Divide the dough in half and roll out half to about three millimetres thick. Cut into even strips, enough to cover the top of the pie dish. Transfer these to a tray covered with non-stick paper and chill or freeze until firm.

3. Turn oven up to 220C (200C fan-forced). Meanwhile, roll the remaining pastry out to three millimetres thick and line the base of the pie dish, with a little pastry overhanging the edge. Pack the pie with the roasted apple and rhubarb.

4. Weave the strips of pastry either completely over the top of the pie, or leave a square bare in the middle. Trim off any overhanging pastry then pinch the edges of the top and bottom crusts together around the edge of the dish.

5. Beat the egg in a small bowl with one tablespoon water. Brush pastry with beaten egg and bake pie for about 30 to 40 minutes until a rich, dark, golden brown on top.

My flaky all-butter pastry can also be used in this apple and raspberry crumble pie.

Find more of Dan Lepard's recipes in the Good Food Favourite Recipes cookbook.