Combine flour and salt in a food processor.

Process butter and shortening until finely cut.

Add 8 tablespoons of water and process until a ball forms, adding more water if needed.

Press the dough into a 1-inch thick round slab.

Roll out the dough (refrigerate if needed to prevent fat from oozing).

Flour your board and rolling pin.

Roll dough from the center to a 1/8-inch thick, 14-inch diameter circle.

Roll dough over a lightly buttered 12-inch tart shell.

Press the dough into the pan and trim edges, creating a 1/2-inch border.

Fold the border back into the pan to double the shell wall thickness.

Roll the rolling pin over the top to trim off excess pastry and refrigerate for 30 minutes.

Preheat oven to 400 degrees.

Place the tart pan on a baking sheet.

Line the dough with foil or parchment and fill with dried beans.

Bake for 10 minutes.

Remove beans and bake 10 minutes longer.

Paint the bottom of the shell with egg and sprinkle with grated cheese.

Return to oven for 3-4 minutes to seal the bottom.

Cool tart shell on a rack for 30 minutes before filling and finishing baking.