Add the flour, sugar, and salt, in the bowl of a food processor fitted with steel blade, pulse it a couple of times to mix well. Add cold diced butter and pulse it 8-10 times or until the fat breaks down into pea-sized pieces. If you don't have a food processor, use a bowl, combine the flour, sugar, and salt and whisk well, add cubes of chilled butter, incorporate the butter into the flour with a fork until it resembles coarse crumbs.
With the food processor running, stream in the cold water through the feed tube until the dough leaves the sides of the bowl. The dough should not form a ball, so stop pulsing when you see the dough beginning to form a ball. Do not over process the dough, some crumbs are fine. I used about 3 tablespoons of ice cold water, you may need more or less depending on the weather conditions, humidity etc.
Turn the dough onto a cling film, flatten it into a disc, wrap and refrigerate it for 1 hour.
Roll out the dough on a lightly floured work surface from the center to the edge into a 10-inch circle and about 1/4th inch thick.
Place the rolled dough in a 7-inch fluted tart pan with a removable bottom, press the dough firmly and carefully at the bottom and the sides of the pan, trim off excess dough from the rim of the pan. Refrigerate it again for 30 minutes.
Preheat the oven to 425 degrees F. Gently pierce the bottom and the sides of the crust with a fork all over.
Bake the tart shell for about 10 -15 minutes or until it is golden brown and let it cool in the tart pan on a wire rack.