In large mixing bowl, stir flour and salt. Cut in shortening and butter with pastry blender or fork.
Add vinegar and 3/4 cup cold water. Add additional water by the tablespoon until the dough comes together to form a smooth ball
Section Dough into 4 equal pieces and flatten each into round disks. Wrap in plastic wrap and chill 15-20 mins.
For 9" deep dish pie crusts - Use your Dough EZ pastry mat. Roll to 12" measures in circle guides. Small dusting of flour may need to be used but mess will be self-contained. Transfer rolled dough to your pie pans and separate top crusts with parchment paper.
Crust can be prepared ahead of time, and place back in the refrigerator or freezer while you prepare filling. Tip: Your Dough EZ mat is temperature safe from -40° to 375°F Making it safe for you to chill it in the freezer to keep dough cold while working with it or Dough EZ is heat safe if exposed to hot baking pans are place on it.
Optional egg wash: 1 egg beaten with 1 Tbs. water. When assembling pie brush with egg and water mixture.