In the bowl of a food processor, place the flour, butter, shortening, and salt.
Pulse until the butter breaks into pea-size pieces.
In a small bowl, mix together the water and egg yolk.
With the machine running, add this mixture to the bowl of the food processor.
Once the dough becomes one big ball, transfer the mixture to a floured work surface and press together into a disc.
Add flour as needed and roll the dough to fit a 9 or 10-inch pie plate.
After placing the dough into the pie plate, trim the edges with a knife, and then crimp the edges with your fingers.
After placing the dough into the pie plate, freeze for 15 minutes.