Place flour and salt in bowl. Cut in shortening until it resembles coarse meal. Sprinkle ice water over surface (1 tablespoon at a time). Mix lightly until it holds together. Do not over-mix. Cut in half, wrap in plastic and keep in refrigerator until ready to roll.
Put apples in large bowl and pour lemon juice over them. In another bowl add dry ingredients and then add to the apples.
Assembly: Roll out 1 of the dough halves to an 1/8-inch thickness. Lay into pie pan with a little bit overlapping the sides. Put apple mixture into pie shell, mounding it higher in the center. Cut cold butter into 1/2-inch cubes and place on top of the apples. Moisten outer edge of bottom crust, place top crust on pie and press down.
Preheat oven to 475 degrees F. When ready to put pie in oven turn temperature down to 450 degrees F and bake on lower rack until it starts to brown, about 15 minutes.
Turn oven down to 375 degrees and bake approximately 1 to 1 1/4 hours