In a medium bowl, whisk together flour, sugar, and salt.  Add cold, cubed butter and vegetable shortening, using a dough blender or potato masher, work the butter into the flour mixture. Continue to do so until butter breaks down into pea size pieces.

Remove the ice and add the cold water to the dough use hands or a fork to mix quickly. You want the dough to start holding a shape, just barely.

Dump onto a floured surface and quickly knead into a disk. Wrap the disk in plastic wrap and refrigerate for at least 1 hour.

Roll out the dough, on a well-floured surface, roll to slightly larger than 10 x 14 inches. Using a ruler and a small knife, trim the edges. Place the dough on the sheet pan lined with parchment paper or a silicone pad and refrigerate while you prepare the apples.

Preheat the oven to 400 degrees F.

Peel apples and cut them into quarters. Using a melon baller and a knife, remove the stems and core. Cut 1/4 inch-thick slices (I usually don't use the rounded ends). Place apples in a medium bowl, add lemon juice immediate to prevent browning. Add cinnamon, brown sugar, and nutmeg and toss until all ingredients are evenly distributed.

Place overlapping apple slices diagonally across the dough. Repeat diagonal pattern all across the tart dough, leaving about an inch space on the edges.

Dot the apples with butter. Bake the tart for 40 - 55 minutes. Rotate the pan half way in between cooking. The apple juices may burn in the pan, but not to worry, the tart will be fine!

When the tart is done, heat the apricot jelly together with the orange juice and brush the apples and the pastry completely with the jelly mixture.