Add flour + sugar + salt in a food processor and pulse to combine.

Drop butter, cut into 1 inch cubes and shortening into the flour and pulse only until butter is cut into flour and pea size crumbs form.

Now add water 1 tablespoon at a time and pulse again to combine. When adding the last tablespoon of water, add drop by drop and pulsing each time adding only as needed.

Pinch into the flour mixture, it should withold the shape. The flour will be still powdery in the processor. Transfer into a work surface, gather into a ball and flatten into a disk. Wrap it tightly in a plastic wrap and refrigerate for atleast 1 hour before before using it.

When ready to roll dust parchment paper with flour, place the disk on it, dust some more flour on the disk, add another parchment paper on top and using a rolling pin roll into a flat sheet. The pie sheet along with the parchment paper can be transferred onto a sheet for baking. Alternately a floured work surface, can be used for rolling. Either way check in between to see if the dough is sticking to the surface and turn sides as needed.