Place the flour, sugar and salt into the bowl of a food processor. Pulse once to blend. Add the cubed butter and shortening. Pulse two or three times to break down the butter and shortening. There should be larger and smaller pieces throughout the flour.
Alternatively you can use a bowl and pastry cutter or knife to achieve the mixture above.
Whisk egg in a small bowl. Add the lemon juice and blend. Add 3 tbsp of the ice water and whisk together. Pour this over the flour and fat mixture. Pulse three to four times, or until the dough starts to come together. Once a ball starts forming, you can dump the contents onto the counter and knead it into a dough ball. If it isn’t coming together in the food processor, add the remaining water.
Alternatively you can toss the egg and water mixture into the bowl and work it in by tossing with a fork until dough begins to form. Working the dough as little as possible, form the dough into a ball.
Divide the ball into two even sections, flatten them, and wrap in plastic. Chill one for the pie below. The other disc can be stored in the freezer till needed. The one in the fridge should chill for an hour to overnight.
Take it out of the fridge for 10 minutes to warm slightly before rolling out. On a well floured surface, roll the dough into a 12 inch round and transfer it to a 9 inch pie plate.
Allow the dough to fall down into the sides and bottom edges, this will ensure that it is not stretched which could cause it to shrink during baking.
Trim dough to a half inch past the edge of plate.
Fold the ends under and crimp with your fingers or fork to shape the edges into whatever design you like best. Chill in the freezer for 15 minutes before adding the filling.