Heat your oven to 180°C /160°C fan/350°F/Gas mark 4.
Grease your loose-bottomed tart tin, making sure you get into the fluted edges.
Cut a large square of greaseproof (parchment) paper big enough to cover the base and sides of your tart tin once crumpled up.
Add your flour and salt to your food processor (fitted with the blade attachment) and whizz for a few seconds until combined. Or mix by hand in a large bowl if not using a processor.
Blob your cubed cold butter over the surface of the flour and pulse until the mixture resembles sand (my processor takes about 20 pulses to achieve this). If not using a processor, rub the butter into the flour using your fingertips.
Add 4 level tablespoons of ice-cold water and pulse again. If the mixture does not easily form large clumps and some flour remains, add another 1-2 tablespoons (I usually need to add 6 to get to the right consistency). If doing this by hand, add the water and mix it in with a fork.
Lightly flour your work surface and tip your pastry mixture out onto it.
Bring the pastry together into a ball but do not knead it. Flatten it out into a circle then roll it out to a diameter of 30-32 cm.
Drape your pastry over your rolling pin and then lay it across your greased tin.
Hold the edge of your pastry vertically with one hand and with the other gently press it into the base of the tin. Once the base is covered gently press into the fluted sides. This video demonstrates a useful method.
The pastry needs to come up about 1cm above the edge of the side of the tin to allow it the capacity to shrink down a little whilst baking.
If your dough tears a little just use some spare dough to patch it up, use a little water if you need to in order to stick the patch on. Keep the spare dough in the fridge just in case you need to patch it up once baked.
Prick your pastry all over the base with a fork and then refrigerate for 30 minutes to set.
Crumple your large piece of greaseproof paper and then place it into the tin so that it covers both the base and sides and then fill with baking beans.
Bake in the centre of your oven for 20 minutes and then carefully tip out your baking beans and remove the paper.
Place the pastry case back into your oven and bake for another 10 minutes or until the pastry is golden all over.