Combine the 3 filling ingredients together and set aside.
For the pastry, cut the shortening into flour and salt mixture, until mealy; beat the egg and mix with the vinegar and water; add to the flour mixture and stir with fork.
Knead on a lightly floured board 3 or 4 times and roll out 2/3 of the dough into a rectangle to fit bottom and sides of a 7"x12 baking dish; ensure there are no leaks and seal tears with a little water if necessary.
Put the berry mixture into the pastry shell.
Roll out the rest of the dough to fit the top of the dish and cut vent holes or designs in the dough; place on the top and crimp the edges together.
Brush the top with milk and sprinkle with sugar.
Bake at 375°F for an hour or until center bubbles.
For juicier cobbler, add a 1/2 cup water before the top goes on.