In a medium saucpan, heat the blackberries over medium heat.
Cook until soft and juices being released, stirring occassionally.
Add the sugar, cornstarch and salt to the blackberrries and stir constantly until the mixture has thickened. 2 to 3 minutes.
Remove from heat and add in the lemon juice. Set asid to cool a little.
Preheat an oven to 425ºF.
Set the baking sheet near your orkspace with a silpat or parchment paper on it. A large baking sheet will hold all 10 hand pies. Use 2 pans if smaller.
Roll out the pastry to about 1/8" thickness and cut 20 3 1/2 inch circles. Re rolling as needed.
Place 10 of the circles on the baling sheet.
Brush the edges of the circles with an egg wash and place a heaped tablespoon of filling in the center. Level out only to 1/4" from the edge.
Cut a shape (star shape cutter) from the center of the remaining 10 discs. You can also just cut a couple of slits if you prefer.
Place the lids on the 10 pastries on the tray. Crimp the edges with a fork. Brush with egg wash and sprinkle with the turbinado sugar.
Bake for 20 minutes until golden.
