Traditional Italian Puff Pastry (Pasta Sfoglia)

1. In a stand mixer, combine 600g of flour with a pinch of salt. Gradually add cold water and mix until a smooth, elastic dough forms. Let it rest under a towel.
2. In a separate bowl, mix the remaining 400g flour with cold butter using the paddle attachment until combined. Shape this into a rectangular brick.
3. Roll out the dough into a cross shape. Place the butter brick in the center and fold over the flaps. Gently roll flat, then fold in thirds like a letter. Wrap and refrigerate for 30 minutes.
4. Repeat the rolling and folding process four times, resting the dough for 30 minutes between each turn. Let rest overnight before using in tarts, pies, or pastries.