Sieve the flour and salt into a large baking bowl

Add the water and mix to a dough.

Leave to rest for about 15 minutes.

Repeat the above another three times and rest the dough in the refrigerator for 10 minutes, or until you need to use it. 

Basically, rolling the pastry will distribute the butter throughout it. The butter must be softened just enough to allow you to roll it in the dough. If taken out of the refrigerator for a short time before use it will be just right.