In large bowl, combine flour and salt.
Add entire cube of chilled butter. Use a pastry blender to cut in butter until mixture resembles course pea sized crumbs. Alternatively, pulse mixture in food processor until largest chunks of butter are about the size of a pea, then transfer to a large bowl.
Alternating approximately 1 tablespoon of extremely cold vodka and water at a time, add liquid to dough mixture and use hands to gently incorporate. Continue adding liquid, alternating small amounts of water and vodka, mixing with hands until dough can be formed into a disk. Avoid adding so much that the dough is wet. You want to add the least amount possible to get the dough to stick together. Take great care not to over work the dough.
Wrap pie crust dough disk tightly in plastic wrap and refrigerate for at least one hour.
To roll, remove disk from plastic wrap and place on a floured surface or in between two pieces of wax or parchment paper and use additional flour, as needed, to keep it from sticking to the surface or rolling pin. Roll into a large circle large enough for your pie dish.
To transfer dough to pie dish, drape over rolling pin and carefully move it into place.