2 cups unbleached all-purpose flour
1 teaspoon salt
3/4 cup vegetable shortening, divided
1/4 cup cold water
4 cups (1 quart) fresh wild
blueberries
1/2 cup white sugar
1/2 teaspoon cinnamon
2 1/2 tablespoons corn starch
Zest and juice of half a lemon
1 tablespoon butter