Place the flour, sugar, butter, and salt in a food processor and pulse until the mixture is just combined (somewhere between 5 and 10 pulses). Add 4 tablespoons water and pulse just until the dough holds together. If necessary, add more water, 1 tablespoon at a time, and pulse just until the dough begins to clump when squeezed with your fingers.
Wrap the dough in waxed paper and refrigerate for 30 to 60 minutes.
Let the dough rest at room temperature for about 10 minutes. Butter and lightly flour an 13-by-4-inch (33-by-10-cm) tart pan with a removable bottom or an 9-inch (23-cm) round tart pan with a removable bottom.
Roll out the pastry dough on a floured work surface to a circle slightly larger than the tart pan. Transfer the dough to the pan, allowing the excess to hang over the edges of the pan. Gently press the dough into the pan. Roll a rolling pin over the top, using the edge of the pan as a cutting surface, and let the excess pastry fall away. Refrigerate for at least 30 minutes.
Preheat the oven to 400ºF (200ºC).
Prick the pastry all over with the tines of a fork, line it with parchment paper, and fill with baking weights. Bake for 15 minutes, then remove the parchment and weights and bake for 10 to 15 minutes more, until uniformly golden with no shiny spots remaining. Let cool to room temperature before filling.