1 egg lightly beaten
1 1/4 cups all-purpose flour
1/4 teaspoon salt
2 tablespoon sugar
4 ounces (1 stick) cold unsalted butter, quartered lengthwise and cubed
3 tablespoons ice water
2 ( 8 or 9 inch) Tarts or 1 covered (8 inch) Tart
Place the flour, salt and egg yolks in a food processor fitted with a steel blade and pulse for 5 seconds to mix. Add the butter and pulse about 15 times, until the butter is the size of small peas. With the machine running, slowly add the water until the dough has formed a ball, about 10-15 seconds. Transfer the dough to floured work surface and lightly knead, about 1 minutes. (It is important not to over-knead the dough. When properly blended, the baked crust will be light and flaky.)
To make by hand, place the flour, salt and sugar into a bowl and stir to mix. Cut the butter into the flour mixture with a pastry blender or two knives, until the mixture resembles a coarse meal. Slowly stir in the egg yolks and then the ice water, mixing thoroughly. Turn the dough out onto a lightly floured work surface and gather it together. Knead the dough roughly and briefly until the dough comes together.
At this point the dough may be patted into place in a tart pan and baked after chilling for 30 minutes in the refrigerator. If you're not patting the dough into the pan, shape it into a flat disk, approximately 1 inch thick, wrap in plactic wrap and refrigerate for at least 45 minutes before rolling it out.
Unwrap the dough and divide it in half for 2 (8 inch) tarts or into 2/3 and 1/3 pieces for a covered tart. Place the larger piece of dough on a floured work surface and roll it out into a circle large enough to fit the pan. Ease the dough into the pan and trim the edges or form a decorative edge.
For a partiallu-baked tart shell, prick the shell with a fork. Line it with aluminum foil, draping ot over the edges to keep them from browning too much and fill with dried beans or pie weights. Bake in a preheated 375 F oven, for 15 minutes, then remove the foil and cool on a rack.
For a pre-baked shell, continue baking for 10 minutes longer or until the shell is golden brown. Cool completely before filling.