1. Combine flour, salt (if desired), and sugar in a medium bowl. Cut in butter with a pastry blender until mixture resembles coarse meal.

2. Beat together water and egg yolks, and drizzle into flour-butter mixture while stirring with a fork. As soon as pastry starts to hold together, stop adding liquid. Shape dough into a flat round, wrap in plastic, and chill for at least 1 hour or overnight.

3. Heat oven to 375 degrees. Remove dough from refrigerator. On a lightly floured surface, roll out to 1/8 inch thick. Press pastry into bottom and sides of tart pan. Run a rolling pin across top to trim. (Scraps can be wrapped in plastic and frozen for later use.) Carefully line pastry with aluminum foil, and weight with beans, rice, or pastry weights. Bake for 10 to 15 minutes. When pastry begins to color around edges, remove weights and foil and continue to bake until pastry turns amber, 10 to 12 more minutes. Place pan on a wire rack and let cool completely before filling.