Combine salt and flour in a large bowl.
454 g Cake flour, 2 tbsp Salt
Cut cold unsalted butter into thumb-width cubes.
454 g Unsalted butter
Toss butter cubes in the flour mixture to coat them.
Working quickly to avoid letting the butter warm up too much, squash the butter cubes flat.
Use a spoon or fork or something that isn't your hand to search for any butter lumps which might need a bit more squashing.
Add the cold water, and bring the dough together into a shaggy ball.
250 ml Cold water
If the dough is warmer than 21ºC / 70ºF let it sit in the fridge for 5 or 10 minutes before proceeding.
On a large and generously-floured surface, roll out the dough into a roughly 45cm / 17in square.
Fold the dough into equal thirds, in from one side, then in from the opposite side
Fold the narrow sides of the dough rectangle into third again, to make a tall folded square
If the dough is warmer than 21ºC / 70ºF let it sit in the fridge for 5 or 10 minutes before proceeding.
Flour dough and work-surface generously, and roll the dough out again, into more of a circle this time, 48-52cm / 19-20in diameter.
Center the dough circle over the springform pan, and let it gently fall into the pan.
Cover the inside of the crust with foil, including the edges.
Gently press the dough to meet the shape of the springform pan. The edge of the dough should still overhang by an inch or more.
Pre-heat the oven to 175ºC / 350ºF.
Cover the exposed dough with foil, including the overhang/edges, and refrigerate for at least an hour.
Place the springform pan on a large baking tray, and bake for 60-75 minutes.
While the crust is blind-baking, prepare the quiche filling.
Check for pastry smell and golden-brown edges.
Remove the foil, use a fork to make a few small holes in the base, and bake for a further few minutes. This helps prevent any bubbling or uneven rising in the base.