Grease a 23cm/9inch fluted loose-bottomed tart tin approx 1.25 inch/3.5 cm deep. Or similar-sized container.
Place the flour, butter and vegetable shortening into a food processor. Blitz until you have a fine breadcrumb consistency. You can also use the rub-in method using your fingertips. But this will take a little longer.
200 g white spelt flour or plain white flour, 50 g butter, 50 g Vegetable shortening such as Trex.
Gradually add enough of the water and bring all the mixture together until you have a ball of smooth, firm dough. TIP: You may not need all the water, so don’t add it all at once.
50 g cold water.
Flatten the pastry a little and wrap it in cling film or baking parchment. Place it in the fridge for at least 30 minutes to rest and firm up. Tip: Leave it overnight in the fridge if you want to bake the next day.
Roll the pastry out between two sheets of baking parchment to about 3 mm thick and large enough to line your tin. Cover the tin and press the dough firmly into the sides and corners, leaving the remaining dough overlapping the sides.
Remove surplus pastry by moving your rolling pin over the top of the tin, cutting through the pastry. Tip: Freeze any offcuts to make a quick pie topping another time.
Neaten the edges and sides using your fingertips, allowing the pastry to lift slightly proud of the top edges. This allows for a small amount of shrinkage during baking.
Prick the pastry base at intervals with a fork. Cover the pastry dough with a sheet of crunched-up baking parchment with overlap on the sides. Return the dough to the fridge and leave for 30 minutes to rest and firm up.
When ready to bake, preheat the oven to 200c deg fan oven. Remove the pastry from the fridge, add enough dried baking beans to cover the baking parchment, and support the sides of the pastry. Bake for 20 minutes in the centre of the oven until the pastry feels dry to the touch.
Remove the baking parchment and baking beans and return the pastry to the oven for two more minutes to dry a little more. When baked, remove from the oven and allow the pastry to cool completely before adding the filling.