In a bowl, beat the water, egg, egg white and vinegar together. Set aside.
In a separate bowl, mix together the 3 cups of flour and salt.
Cut the shortening into the flour mix with a pastry blender or two butter knives. Make a well in the center of the flour mix and pour the liquid ingredients from the first bowl into the center.
Mix the wet and dry ingredients with a fork until it becomes stiff.
Turn the dough out onto a lightly floured surface. Knead it just until all the flour is incorporated and the dough is smooth.
Wrap the dough in plastic and refrigerate for at least 1 hour, but never more than 24 hours.
Prepare the work surface by lightly flouring the area where you plan to roll out the dough.
Tip: If you want to keep the dough longer than 24 hours, you can freeze it.