Toss the defrosted blueberries with the tapioca and set aside.

Preheat the oven to 400°F. (375°F if you are using a convection oven)

Prepare pie crust:

1. In the bowl of a food processor combine flour, sugar and salt. Process for 30 seconds.  Distribute the butter pieces evenly over the flour mixture.  Pulse 4 times.  Distribute the shortening pieces over the flour mixture.  Pulse 8 more times.  Place mixture in a large bowl.
2. Add the cold water in a tablespoon at a time and use a fork to blend until mixture starts to come together and is no longer dry (do not make too wet.)  Divide dough in half and flatten into two round discs. Wrap one of the discs and refrigerate.
3. Flour your board and rolling pin. Roll out one of the discs into a rough circle big enough to line a 10″ pie pan. Carefully place into the pan pressing into the bottom and sides then trim the crust even with the edges of the pan; set aside.
4. Roll out second disc the same size as the first. Using a knife or pastry wheel cut the pastry into 10 – 1″ thick lattice strips; set aside.
5. Combine the sugar, cornstarch, cinnamon and nutmeg. Fold into the berry/tapioca mixture. Add the lemon juice and mix well.
6. Pour the filling mixture into the bottom crust. Place 5 lattice strips vertically and evenly over top of filling making sure edges overlap the edges of the pie tin. Alternately lift three of the pieces folding them over themselves halfway. Place a long lattice strip horizontally over middle of pie overlapping the two unfolded lattice strips. Now, pull the folded strips back over to their original positions. Then fold the alternating two strips over the horizontal strip. Place another strip horizontally overlapping the three unfolded lattice strips. Pull those folded strips back over and repeat the process for the last piece of lattice. Rotate the pie 180 degrees and use the same process to weave the lattice strips starting with two alternating strips of lattice. When all 10 strips have been placed, fold the edges over and under the bottom pie crust then flute the edges of the pie.
7. Carefully brush the top of the lattice strips with egg wash, cover  the edges of the pie with a foil band and bake for 35 to 40 minutes until the top is golden brown and blueberries are just beginning to bubble. You can place a piece of foil on the rack below the pie to catch any drippings.
8. Remove from oven and cool.
9. Serve and enjoy plain or with some vanilla ice cream.