Prepare pastry for a 2-crust 9 pie. Roll out half of the pastry and place in 9 pie pan.
6 cups fresh blueberries - wash and drain dry
1 cup sugar
6 Tbs flour
1/8 tsp salt
¼ tsp cinnamon
1 Tbs fresh lemon juice (optional)
1 Tbs butter (in small pieces)
Mix together the sugar, flour, salt and cinnamon. Spoon 2 Tbs of the sugar mixture onto the pie crust. Top with half the blueberries. Sprinkle with half the sugar mixture. Repeat with remaining berries and sugar. Top berry mixture with lemon juice and dot with butter.
Place top crust over filling. Seal and flute the edges. Cut vents in the top crust. Brush crust with an egg wash (an egg beaten with a little milk or water). Put piece of tin foil under the pan in the oven, in case the juices overflow. Bake at 450 for 20 minutes, then at 375 40 minutes.