Shred the 1 1/2 frozen sticks of butter into 2 separate containers and place back in the freezer. Cut the remaining 1/2 stick of butter into small cubes (about 1/4 inch) and chill in refrigerator for a few minutes.

In a large bowl, add the salt to the flour and mix. Add the 1/2 stick that was cut into cubes and mix into the flour using your fingers until all the flour appears lumpy. This will take some time. Add the cold water 2 tablespoons at a time mixing into the flour until it has the consistency of dough.

Roll out the dough into a rectangle on a lightly floured surface: the length should be 3 times longer than width. Don't over-flour the surface nor the rolling pin too much or it will affect the rise of the dough later. Lay the first of the frozen, shredded butter on the lower 2/3 of the dough. Fold down the top 1/3 and fold up the lower 1/3 (as if folding a letter). Rotate the dough 90 degrees and roll out into a rectangle again. Repeat with the remaining frozen, shredded butter. Rotating 90 degrees then folding and rolling one last time. Wrap in cling wrap and put in the refrigerator at least 30 minutes. It can also be frozen until needed but you must let it thaw in the refrigerator before using.

Preheat oven to 425 °F. Roll out the dough on a lightly floured surface until it is 1/4 to 1/8 inch thick. Prepare into the shape desired, fill it with sweet or savory fillings and place on a baking sheet. No need to oil nor coat the baking sheet. Brush the tops of the pastries with the egg wash.

Place in the oven. After 10 minutes lower the temperature to 375 °F or 400 °F and leave another 10-15 minutes until golden brown. Remove from the oven and let cool for a few minutes. For sweet fillings, you can coat the tops with confectioner's sugar when the pastries have cooled down a bit.