Place the flour in a large mixing bowl
Add the frozen, grated salted butter and stir with a fork until everything is well combined and you have lots of little pea size pieces of butter coated in the flour
Add the icy cold water and stir with the fork until it ls all mixed together
Sprinkle your hands with flour and get in the bowl and knead the dough together with your hands until it forms a ball.
Empty the ball out on to a lightly floured surface
Sprinkle some flour on your rolling pin and roll the dough out in to a large rough rectangle. Fold the dough in to thirds, turn a quarter turn, then roll out in to a rectangle again. Fold the dough in to thirds again, turn a quarter and repeat that process six times.
Divide the dough in to two pieces, wrap each tightly in plastic wrap, place in a Ziploc bag and let rest in the refrigerator for at least an 1-2 hours, but up to 48 hours before using it.
When ready to use, let dough sit on the counter for 15-20 minutes before rolling out.