Mix sugar-cinnamon mixture gently through the apples and set aside.
For the crust, mix the flour and salt together.
Add the oil, mixing with a fork or pastry blender until it looks like fine crumbs.
Sprinkle the milk and gently mix inches.
Gather the dough together so that it forms a ball. Do not over-handle the dough as you will end up with a tough pastry.
Divide pastry in half, and roll between two strips of waxed paper. (If you moisten your surface with a damp cloth, the waxed paper will not slip around.).
Roll in a circle about 12 inches in diameter.
Peel the top sheet of waxed paper off the pastry, gently fit the crust in a 9-inch pie pan (crust down), and gently peel off the paper. If you like, you can trim the crust leaving about 1/2 inch overhanging.
Heap your apple filling into the pastry-lined pan. (If you are using frozen filling, you may want to add 1 tablespoons cornstarch just in case the filling is too juicy -- no one likes a soggy pie!).
Roll top crust the same way as the bottom crust and place over the filling, trimming about 1/2 inch beyond the pan rim.
Fold the crust under and flute or use whatever decorative edging you like. The easiest way is to just take the tines of a fork and seal the two crusts together, working around the pie pan and then trim the excess.
Cut some slits in the top crust to let steam escape.
Cover the edges of the crust with a strip of aluminum foil to prevent over-browning of the edges. Set the pie on a pizza tin or a pan to collect any juices that might overflow.
Bake 50 minutes, then remove the strips of aluminum foil and bake 10 more minutes.