In a large bowl, mix the washed blueberries with the sugar, the corn starch and the lemon juice.
Set aside.
Preheat the oven 350F (180C).
Roll the first ball of pie crust on a floured surface about 1/4 of an inch thick (0.5cm) and a little bit larger than the size of your pie pan.
Place the crust in the pie pan and press the edges. Cut the edges.
Pour the blueberry mixture onto the pie crust and spread all around.
Roll down your other ball of pie crust.
Using a cookie cutter, cut little pieces of dough.
Place those pieces on top of the blueberry filling covering most of the pie but leaving some holes for the steam to escape.
Brush the top of the blueberry pie with egg wash and sprinkle some sugar on top.
Bake for 40 to 45 minutes.
