Combine flour and salt in a bowl or the bowl of a food processor. Next, add the shortening and pulse until a crumbly texture is achieved. Combine the egg, 4 tablespoons ice water and vinegar and add this mixture to the food processor stirring until the dough forms into a ball and pulls away from the sides of your container. Add more water if necessary. Remove dough from the processor and shape into a disk. Cover with plastic wrap and chill in refrigerator at least one hour. I made mine a day ahead to save time and it was the perfect consistency.