In a small bowl, add the salt to the water and stir to dissolve. Keep cold until ready to use.
Place the flour in a large mixing bowl. Cut the butter into 1-inch (or smaller) pieces and scatter the pieces over the flour. Using a pastry blender or two knives or two forks, cut the butter into the flour until the mixture forms large clumps and the butter is in pieces the size of small peas. Drizzle the water-salt mixture over the flour and stir and toss with a fork until the dough comes together in a shaggy mass. Gently mix until the dough comes together into a ball but is not completely smooth.
On a lightly floured work surface, divide the dough into 2 equal balls and shape each ball into a disk 1-inch thick. Wrap well in plastic wrap and chill for at least 2 hours or up to overnight.
Preheat the oven to 375ºF.
Place dough on a lightly floured surface and roll out to ⅛-inch thick, rolling from the center toward the edge in all directions. (Lift and rotate the dough a quarter turn every few strokes to prevent sticking, and work quickly to prevent the dough from becoming warm.) Transfer the round to the pie dish, easing it into the corners. Trim excess dough.
Cut a piece of parchment paper large enough to fit over the pie plate generously. Fill parchment paper with pie weights or dried beans. Bake for about 25 minutes or until the surface looks light brown. Remove from oven and remove the weights and paper. Return the shell to the oven and bake until golden brown, about 5 minutes longer. Cool shell on wire rack until ready to fill.
If you only want to make 1 tart shell, halve the recipe. The dough freezes well, too.
Recipe by How to Decorate at https://www.ballarddesigns.com/howtodecorate/2014/05/recipe-flaky-tart-dough/