Blueberry Lattice Pie

6 cups blueberries
4 tablespoons tapioca starch flour
1 - 1½ cups sugar
juice of one lemon
pinch fine sea salt
1 recipe pie dough
2 tablespoons unsalted butter, cut into pieces

-Toss together the fruit, flour, sugar, lemon, and salt. 
-Roll out bottom crust and place in pie dish. 
-Add filling and sprinkle pieces of butter on top. 
-Cover with top crust and crimp.
-Place pie on baking sheet lined with parchment
-Bake in 350° oven for 1 to 1½ hours, until filling is bubbly. 
-Allow to cool before cutting.