Add the flours, sugar, and salt into food processor; pulse to combine. Cut the butter into cubes, add, and pulse until the butter combines with the mixture into coarse crumbs. Be careful not to over-mix - you don't want a tough pie crust.

Start the processor running, and slowly add the water. Be careful again not to overmix; the processor should not run for more than 30 seconds. The dough should squeeze together; if it is too crumbly, add water 1 tablespoon at a time. Remove the dough from the processor, and shape into a circle. Wrap in plastic wrap, and chill for 30 minutes to one hour in the fridge. (I chilled in the freezer for 10-15 minutes, and was able to work with the dough well).

Meanwhile, prepare the filling by combining the blueberries, flour, sugar, salt, and lemon juice in a bowl.

Preheat the oven to 400*. After chilling, remove dough from plastic wrap. Lightly flour a clean, flat surface and divide dough into two. Roll each piece into the diameter of the crust. Grease the pie pan and place one of the crusts in it, conforming to the pan. Fill with the blueberry mixture.

Top with the second crust: you can simply place it on top and crimp together the edges, or cut it into pieces to create a lattice or other design crust.

Bake at 400* for 10 minutes, then 375* for 20-25 minutes. (If your oven in older like mine, you may need to add a few more minutes at the end.)