[I like to make my pie crust in a food processor because it is faster and easier.] With the knife blade attached, pulse flour and salt to mix. Evenly distribute butter and shortening on top of flour mixture; pulse just until mixture resembles coarse crumbs. With processor running, pour 4 tablespoons ice water through feed tube. Immediately stop motor and pinch dough; it should be just moist enough to hold together. If not, with fork, stir in up to 2 tablespoons additional ice water. Refrigerate and roll as directed.
The moistness of the crust is important. If its too dry, it will tear and crack as you roll it. My crust is about the consistency of Play Dough. Flour your work surface and roll out half your dough, dusting the top with flour so your rolling pin doesn’t stick. Turn your dough 1/4 turn every few passes of your rolling pin. When you reach 1/4″ thickness, roll your crust around your rolling pin and then unroll it over your pie plate.
Preheat the oven to 425. In a large bowl, toss the lemon juice with the blueberries. Add the sugar, salt and cornstarch, and toss again. Add to prepared pie dish and dot with butter. Roll out the other half of your dough in the same manner as the bottom crust. Roll it out over the fruit and crimp the top and bottom crusts together decoratively. Cut slits in the top crust to allow steam to escape. Alternatively, you could also do a lattice top crust (see picture). Beat the egg and brush it on the crust and sprinkle with sugar.
Set the pie on a foil-lined cookie sheet. Bake in preheated oven for 20 minutes. Turn the oven down to 375, continue to bake for one hour. Check on your pie after about 45 minutes; if its already nicely browned, cover with foil. Let cool to "warm" before cutting.
Note: The original recipe calls for 1/4 c cornstarch. As I was writing this morning, I noticed that I COMPLETELY misread the recipe when I was going at 90 mph the other day. I added
of cornstarch (in hindsight, I did think to myself, "Boy that seems like a lot of cornstarch... but then again, blueberries release so much liquid, maybe thats why?"), but it also ended up (surprisingly) being a mistake that turned out just fine. One of my big issues with pies is that I always seem to end up with liquid-y fillings. Not this time, haha! So I did recommend increasing the amount of cornstarch to 1/3 cup. Since I didn't even notice my error until this morning, even after having eaten it, it couldn't have been too bad...