In a large bowl, sift the flour (and salt if adding). Next, cut cold butter into cubes. If it is not ice cold, place the cubes of butter in the freezer for at least ten minutes.
Using a pastry cutter or two forks, break the butter into the flour until it resembles a coarse meal with some pea-sized pieces of butter.
Make a small pit in the center of the flour and slowly 4 tablespoons of cold water and use a spatula to mix until the dough holds together and forms a ball. If the dough does not come together or feels crumbly, feel free to add in more water 1-teaspoon at a time
Coat your hands in flour and begin to form the dough into a round disc. Then, wrap the dough in plastic wrap and transfer it to the fridge for at least 45 minutes before using. When you are ready to use the dough, remove it from the fridge. If it is hard to manipulate, let the dough sit at room temperature for 10-15 minutes before rolling it out
Transfer the dough onto a lightly floured surface and begin to roll out the dough into a 12-14 inch circle until it is about 1/8 - 1/4 inch thick. If needed, place a piece of parchment paper on top of the dough to help when rolling it out
Line a baking sheet with parchment paper. Transfer the crust onto the prepared baking sheet. Add the filling of your choice to your crust, making sure to leave at least a 1-2 inch border. Fold the border over the filling, then brush with egg wash to achieve a golden crust.