Using your rolling pin, beat the butter into an evenly-thick square. You may need to mess around with it a bit to get this into a uniform thickness.
Set the butter packet aside. It should be cold and firm but not hard (also, if it’s getting too soft, put in the refrigerator) while you roll out your dough.
Flour your rolling surface well with gluten-free flour. Take the dough out of the refrigerator and unwrap from the foil. Place the dough on the rolling surface. Starting from each of the 4 sides, roll out flaps from each side, leaving a roughly 4″x4″ square of thick dough in the center.
Remove the butter packet from its plastic wrap and place it on top of the thick part of the dough. The butter packet and the dough should be roughly the same length and width.
Carefully fold the flaps of dough over the butter, one at a time. When all four flaps are over the butter, it will look like an envelope.Press the dough around the butter packet to seal it in.
Make sure that the butter is completely encased in the dough. You don’t want any of the butter to squeeze through any holes.
Now you are ready to do the first “turn.” Add some more flour to your rolling surface (make sure it is well floured at all times). Also, make sure your rolling pin is floured, as well. Now carefully roll your dough out in a long rectangle. (The rectangle should be roughly ½ inch thick and about 3 times as long as it is wide.)
And now you do the first fold. I recommend doing the single fold method. (Simply take one end of your dough and fold roughly a third of it onto the top of the dough.) Then take your other end and fold it on top of the already folded dough–as you would with a letter.
With a floured knuckle, make one single impression on the dough, to represent the completion of one turn. Cover the dough with plastic wrap and place in the refrigerator until firm, about 15 minutes.
Once the dough is firm, remove it from the refrigerator, flour the outside and once again, with a long side of the folded dough facing you, roll away from you and into a long rectangle about ½ inch thick. Fold once more, and mark the dough twice with your knuckle, to represent two completed turns. Refrigerate until firm, and repeat the process of rolling, folding, marking and chilling for at least 4, and up to 6, turns.
Once you’ve repaired your dough and have made it look as neat as possible, wrap tightly in plastic wrap and refrigerate or freeze until ready to use. If you freeze the puff pastry, defrost overnight in the refrigerator before using.
Bake it at 400°F (200°C) or above.