1. Take the butter out of the fridge about 10 minutes before you want to use it, no longer. It should start to soften but still be cold.
2. Tip out your flour into a mound on your kitchen top.
3. Cut the butter into 2cm cubes, then add to the flour. 'Pinch' together using your thumb and index finger until loosely combined. The butter should still be quite chunky, you don't want a fine crumb. This will take 2-3 minutes.
4. Distribute the butter evenly, then form a watertight ring using the mixture, with a well in the centre. Add the water to the well.
5. Working quickly with a bread scraper, bring in the flour from the outside of the ring, to the centre, so that it absorbs the water. If you do this well, the flour and butter should not have any leaks where the water runs out. No matter if it does, just work a bit faster until all the water has been absorbed by the flour and butter.
6. At this point, bring the ingredients together to form a rough dough, taking care not to overwork it.
7. Flour your work top and the rolling pin, then roll out the dough to around 45cm long 20cm wide; a long, thin rectangle. Take the top short end and fold down 2/3 of the way of the length of the dough. Take the bottom short end and fold up over that. You should have a neat rectangle. Turn the rectangle 90 degrees, re-flour and repeat the process, 4 times in total.
8. When you've finished rolling and folding, cling film and leave to rest in the fridge for at least an hour, until ready to use. This freezes really well too.