In the bowl of a stand mixer, combine the flour and the salt and mix until incorporated.
Add the cubes of cold butter and, using your fingertips (or a pastry blender), work the butter into the flour until the mixture resembles coarse meal.
In a separate bowl, beat the egg, ice water and white vinegar together.
Add to the flour/butter mixture and, using the dough hook, mix in the stand mixer just until the dough comes together. (You can also skip the mixer and do this by hand!)
Form dough into a flat disc and chill, wrapped in plastic wrap, for at least one hour.
After dough is chilled, divide into 12 equal parts and roll each part into a disc (1/8 inch thick). You can use a large cookie cutter to cut the disc into a better circle. I usually don't worry about it, as I don't mind my empanadas being different sizes! It gives them character! :)
Place the filling in the center of the circle and carefully fold the empanada into a semicircle.
Crimp down the edges with a fork. If necessary, wet your finger and rub it along the inside edge of the dough.
To fry the empanadas, heat vegetable oil (enough to cover the empanadas) to 360F degrees and fry the empanadas until golden, about 2 minutes per side. I like to add a few cloves of garlic to my oil. It makes the empanadas even more flavorful!
Transfer the empanadas to a plate lined with paper towel.
Serve hot!