Perfect Tart Crust
Measure the dry ingredients into the bowl of a standing mixer attached with the steel blade. Quarter the chilled butter lengthwise and cut crosswise into 3/8-inch pieces; add to the flour along with the chilled shortening. Pulse the mixer 4 or 5 times. Turn the machine on and pour in the water, and immediately pulse the mixer on and off several times. The dough should begin to mass on the blade. If not, drizzle in a little more water and repeat, repeating again if necessary. Dough is done when it has begun to mass; do not over mix it. Scrape the dough out onto your work surface and proceed to the fraisage.
With a scraper or spatula, gather the dough again into a mass; knead it briefly into a fairly smooth round ball. Sprinkle it lightly with flour and wrap it in waxed paper. Either place the dough in the freezer for about 1 hour until it is firm but not congealed, or refrigerate for 2 hours or overnight. (Uncooked pastry dough will keep for 2 to 3 days under refrigeration, or may be frozen for several weeks. Always wrap it airtight in waxed paper and a plastic bag.)
Rolling out the dough: Because of its high butter content, roll out the dough as quickly as possible, so that it will not soften and become difficult to handle. Place the dough on a lightly floured board or marble. If the dough is hard, beat it with the rolling pin to soften it. Then knead it briefly into a fairly flat circle. It should be just malleable enough to roll out without cracking.
Lightly flour the top of the dough. Place rolling pin across center and roll the pin back and forth with firm but gentle pressure to start the dough moving. Then, with a firm, even stroke, and always rolling away from you, start just below the center of the dough and roll to within an inch of the far edge. Lift dough and turn it at a slight angle.
Give it another roll. Continue lifting, turning and rolling and, as necessary, sprinkle the board and top of dough lightly with flour to prevent sticking. Roll it into a circle 1/8-inch thick and about 2 inches larger all around than your pie pan or flan ring. If your circle is uneven, cut off a too-large portion, moisten the edge of the too-small portion with water, press the 2 pieces of pastry together and smooth them with your rolling pin.
The dough should be used as soon as it has been rolled out, so that it will not soften.
Prebaking the pastry shell: Partial baking sets the dough and is a safeguard against soggy bottom crusts. Line the pastry with buttered lightweight foil or buttered brown paper, press it will against the sides of the pastry and fill it with dried beans. The weight of the beans will hold the pastry against the mold during the baking. Bake at the middle of a preheated 400-degree oven for 8 to 9 minutes until pastry is set. Remove mold or foil and beans. Prick bottom of pastry with a fork to keep it from rising. Return to oven for 2 to 3 minutes more. When