First, grate the 180 grams butter and put back into the freezer.
Put flour and salt into a large bowl and stir to combine.
Rub in the 75 grams of cubed butter.
Gradually add water and stir with hands until dough forms.
Knead a few times on a floured countertop to bring the dough together.
Roll out dough to a 10 inch x 15 inch rectangle on a well-floured counter top.
Sprinkle frozen, grated butter over ⅔ of the rectangle. Fold bottom third up and then top third down.
Seal edges and roll out to a 10 inch x 15 inch rectangle again. Fold in thirds, like a letter. Wrap in cling film and freeze for 10 minutes.
Remove dough from freezer and roll out again to 10 inch x 15 inch rectangle. Fold in thirds again, seal edges, wrap and refrigerate until ready to use.
When ready to use, generously sprinkle counter with powdered sugar. Roll out pastry, sprinkle the top generously with powdered sugar and cut pieces in desired size. I prefer 3 inches x 2.5 inches. I got 9 three-tier mille feuille out of this batch.
Place the pieces on a baking sheet that is lined with silpat or parchment paper. Refrigerate until ready to bake.
Dock dough with a fork several times to keep from puffing too much. Sprinkle again with powdered sugar. Place another silpat or piece of parchment paper on top. Add two baking sheets on top to weight down the pastry. You can also add another heavy item that is oven proof like a cast iron pan. Refrigerate until ready to bake.
Preheat oven to 425℉ about 20 minutes prior to baking. Bake for 15 to 20 minutes, remove top baking sheet and parchment. Bake another 5 to 10 minutes or until done.
Remove from baking sheet and allow to cool.