Heat apple juice and cornstarch in saucepan, stirring constantly. Stir in margarine, cinnamon and a pinch of salt. Pour over apples in a bowl, mixing carefully. Spoon apple mixture into pastry-lined pie plate; cover with remaining pastry. Brush pastry with melted margarine. Bake at 357 degrees until crust in golden brown. To cut down to fat, I sometimes omit a full top crust and use apple for some other cutout and decorate the top with them. Lite margarine such as Bluebonnet or Parkay will met and give fewer fat calories.