1. Rub in 4 tbsp butter and all the shortening into the flour until the mixture resembles coarse bread crumbs. Stir in enough water to make a dough that holds together. Gather into a disk. Wrap in plastic wrap and refrigerate for 30 minutes.

2. Preheat the oven to 425°F (220°C). On a floured surface, roll out the pastry to a 15in (38cm) round. Transfer to a baking tray, hanging the excess over the sides.

3. Peel, core, and cut the apples and pears into ¼ in (5mm) thick slices. Arrange the fruit in concentric circles on the pastry, leaving a 1½ in (4cm) border. Sprinkle with the sugar and dot with 2 tbsp butter. Fold up and pleat the pastry around the fruit.

4. Bake 45 minutes, or until the fruit is tender and the crust is golden brown. Brush with the preserves. Serve warm.