Combine the flour, salt, sugar, butter and shortening in the bowl of your food processor and pulse several times until the mixture resembles coarse sand. *Alternatively, you can use a pastry cutter to combine the ingredients in a large bowl.
Add 1/4 cup of cold water to the food processor or bowl and mix until the mixture starts to form a dough. Add more water if needed. I find that 1/4 cup plus 2 tbsp is the perfect amount for me.
Turn the dough out onto a lightly floured surface and quickly shape into a large ball. Divide the ball in two, and shape each dough ball into a small flat disc, about the size of your palm. *Work quickly with the dough, as warm hands will melt the butter and not give as flakey of a crust as desired.
Wrap the discs with plastic wrap and refrigerate for at least 30 minutes and then use. *If using the dough at a later time, let it sit on the counter for at least 10-15 minutes before rolling out on a lightly floured surface.