In a large bowl, whisk together flour and salt.

Add cold butter cubes and use a pastry cutter or your fingers to blend until the mixture looks like coarse crumbs with some pea-sized pieces.

Gradually add ice-cold water, mixing just until the dough begins to come together. Avoid overworking.

Shape the dough into a rectangle, wrap in plastic wrap, and chill for 30 minutes.

Roll dough into a rectangle and fold into thirds, like folding a letter.

Rotate the dough 90 degrees, roll it out again, and fold into thirds again.

Repeat rolling and folding two more times, chilling 15 minutes between each fold.

Use the dough immediately or wrap tightly and freeze for later use.