Combine the flour, salt and butter in a food processor and pulse until the mixture resembles coarse crumbs.

With the processor running, slowly add the water until the dough forms into a ball. (You may have to stop and scrape the dough from the sides to be sure it is all blended.)

Roll the dough into a ball and divide it in half.

Then on a lightly floured counter, press each half into a disk.

Wrap in plastic separating the two disks with waxed paper and refrigerate for at least one hour.

In a suitable bowl combine the blueberries, sugar, Tapioca, lemon juice and cinnamon.

Heat the oven to 450F degrees.

On a lightly floured surface (I use parchment, butcher paper or freezer paper) roll out one pastry disk (recipe above) to a 10-inch round.

Carefully fit it into the deep-dish pie pan.

Trim the crust allowing for about a 1-inch overhang.

Mound the filling mixture onto the pie shell.

Roll out the other pie crust disk large enough to cover the top pie with some overhang.

Trim the top crust, fold the edge under the bottom crust and crimp the two together.

Cut steam vents in the top crust.

Brush the top crust with the egg yolk and sprinkle the cinnamon sugar mixture over the top crust.

Bake at 450F degrees for 10 minutes; then reduce the temperature to 350F degrees and bake for 50 minutes longer.

Let the pie cool before cutting into individual serving-size pieces.