The main thing about pie crust is that you shouldn't mess around too much with the dough - the less you mix it after it's all combined, the better. In a medium bowl, combine flour and salt. Using two (2) knives, dice up the room temperature shortening until they are little cubes a few cm long. They should be like small crumbles of shortening. 

In a small bowl, beat the egg, vinegar, and cold water together until blended. Slowly pour the liquid over the flour and shortening mix and stir gently with a fork until it is all covered. At this point, make sure your hands are clean and free of rings because you're going to get right in there and squeeze the dough together. Do this until there are no dry chunks anymore and the shortening is combined well into the dough. You may need to add more cold water but be careful with how much you add as you don't want runny dough. Form into a ball and place in the fridge for 15 minutes. 

While this is in the fridge, start your pie filling on the stove. Start with your cut up fresh peaches in a sauce pan over low heat -- if you are using frozen or canned, skip this step! In another saucepan on medium heat, combine water, lemon juice, brown sugar, and cornstarch. Cook until it is thick and starting to bubble (around 5 minutes).

Keep stirring for 3 minutes while the mix is bubbling, take the pan off the heat and then add the vanilla extract, cinnamon, and peach slices in.

Cool the filling in the fridge or leave until it comes down to room temperature. 

Preheat the oven to 350F. Take the dough ball from the fridge and split into two (2). On a heavily floured surface, roll out the ball with a floured rolling pin. Heavier rolling pins do the work for you, so I would suggest a marble one.

Roll one ball evenly until just larger than the circumference of the pie dish - about just bigger than 10" usually. I roll to about 2-4cm thickness - depends how thick you like your pastry! When moving the pie crust to the dish, flour the surface of the pie crust, fold in half gently, slide the pie dish behind the halved crust, and then gently pull the crust into the dish. If there are any really far out crust bits, use a sharp knife to trim the dough until there is just enough to cover the tops of the sides. Use a fork to poke holes all over the crust and then press down on the tops of the dough sides with the flats of the fork tines. 

Put in oven for about 10 minutes to pre-cook the crust. With the other ball, roll out the dough the same way. Cut strips about 1 inch thick for the top pastry - keep in mind some will be longer than others. 

Take the filling out of the fridge after taking the pre-cooked crust out of the oven, and add the filling to the pie. Take the strips of dough and place across the pie like a cross hatch and again, trim off any super long pieces. You can smush the ends around the top of the dish so the pieces don't just hang. Use a pastry brush to brush the egg wash over the strips and sprinkle lightly with a bit more cinnamon. Pop back in the over for 30-40 minutes, checking periodically. Pie should be a nice toasty brown when finished.