Puff pastry

Dough laminated with butter in many thin layers. In the oven the water in the butter turns to steam and lifts the layers apart. Keep it cold until it goes into the oven. The layers take up water fast, so a wet filling makes the base soft unless the base is blind baked and sealed. To join two sheets, overlap them by 20 mm, brush the overlap with water, press and roll once over the seam.