In a food proccessor, put the flour, sugar and salt, and process until well combined. You can also do this in a bowl by using a fork to combine the ingredients, just don´t use your hands, as your body temperature will mess with it.
Now add the butter and vegetable shortening and process until the mixture is sand-like (again, you can also do it using a fork).
Then add the cold water and the white vinager and mix again until a soft dough is formed.
Wrap this dough in plastic kitchen paper and leave it rest in the fridge for 30 min.
Take the dough out of the fridge and roll it out until it´s about 0.2 inch (5 mm) thick. Place the rolled out dough on a pie mold and press it using your fingers for it to cover the whole pie mold surface. Now shape the edges of the crust using your fingertips by making a pinching motion.
Cover the crust with parhcment paper or aluminium foil and place something on top of that to make it press onto the crust. You can use raw beans, rice, etc.
Bake at 375°F for 10 minutes, then take the parchment paper away and bake it for 10 more minutes.
Take it out of the oven and let it cool a little before adding the filling.
For the filling:
Reduce the oven temperature to 350°F (180ºC).
In a big bowl, mix all the ingredients using a hand whisk.
Pour the mixture onto the pie crust and bake again for 50 to 60 minutes.
The pie will be ready when the edges look a little dry but the center still jiggles a little.
Take the pie out of the oven once it´s ready, let it cool down for an hour at room temperature and then put it in the fridge for at least 4 hours.