• For the ice water, put ice 4 or 5 ice cubes in a measuring cup and fill it with cold water to about a cup.
• Cut 1 cup unsalted butter into small pieces. Keep it refrigerated if while measuring the rest of the ingredients.
• By hand: place 2 ½ cups all-purpose flour, ½ teaspoon salt and 1 tablespoon sugar in a large mixing bowl and stir to combine. Scatter the cold butter pieces and integrate until the butter is the size of pean and beans. It will be irregular. Use your hands or a pastry cutter or dough blender. Add about ½ cup of ice water and stir to mix with a fork. Add ¼ cup more ice water and mix to integrate until it barely comes together.
• In a food processor: put 2 ½ cups all-purpose flour, ½ teaspoon salt and 1 tablespoon sugar if using. Add the cold diced butter and pulse on/off until the butter is the size of peas and beans. Add about ½ cup of ice water and pulse a few times. Add ¼ cup more ice water and pulse until it barely comes together.
• Check the dough. Even though it's crumbly and dry, if you take some and squeeze it with your hand, it should come together. If it doesn't come together, add a teaspoon more at a time. Be careful of adding too much water. It should not be wet and sticky.
• Transfer dough to a barely floured surface and gather it together into a ball. Don't overwork it or the dough will be tough. Wrap in plastic and refrigerate for an hour or up to 3 days.

Lining the pan:

• When you're ready to use it, roll it on a lightly floured surface, starting from the middle and making sure the size is at least 1 inch bigger than the pan you're using.
• Carefully place in the ungreased pie pan. Trim edges, prick the surface and refrigerate for 1 hour or freeze for half an hour. This resting period helps with achieving a flaky pastry. 

Blind-baking:

• Preheat oven to 350ºF (180ºC)
• Put foil and weights (I use dried beans) covering the dough surface and bake for 10 to 15 minutes. Lift foil and weights and continue baking for 10 more minutes, or until it's dry and starting to color.