Combine flour and salt in a bowl. Cut in shortening with a pastry blender until mixture resembles coarse meal.
Whisk together 6 tbsp (90 mL) ice water, vinegar and beaten egg.
Gradually add ice water mixture to flour mixture, mixing lightly with a fork just until dough starts to hold together. If dough is too dry, gradually mix in additional ice water, 1 tsp (5 mL) at a time, just until dough comes together.
Gather dough into a ball; divide in half. Flatten each half into a disc shape. Wrap each disc with plastic wrap and refrigerate for 2 hours before rolling out.