Mill your wheat and set aside.
In a stand mixer fitted with a roller or paddle attachment, add your room temperature butter, flour, powdered sugar and salt.
Mix until the dough is combined and there are no visible chunks of butter.
Take an 8"x8" square pan (single recipe) or 9"x13" (double recipe) and line with parchment paper. The paper should go up the sides of the pan enough to cover the pan when the lemon curd is poured on top of the crust. I use premeasured sheets that come up the sides of my 9"x13" 3/4 of the way.
Pour your dough into the lined pan. Using your floured hands or a small rolling pin, flatten the dough evenly into the bottom of the pan. Press into the corners and edges well.
Next, take a fork and prick the dough all over. This will prevent it from getting air bubbles and baking unevenly.
Move an oven rack to the bottom 1/3 of the oven.
Place the dough in the refrigerator for 20 mintues while you preheat your oven to 350℉.
Place dough in the oven and bake for 15-18 minutes (8"x8") or 20-22 mintues (9"x13").
You want your dough to just be slightly brown around the top edges.
Remove from the oven an allow to cool slightly while you make the lemon curd filling.