In the bowl of a food processor combine the flours, salt, and butter.
Pulse a few times until the butter is roughly the size of peas.
With the food processor running, add the ice water 1 tablespoon at a time until the pastry begins to come together. It should still be a bit crumbly, but when you squeeze it in your hand it should hold together.
Turn the pastry out onto a lightly floured surface and use your hands to form it into a smooth disc. Wrap with plastic wrap, and place in the fridge to chill for at least 30 minutes. You can also make this a day or two ahead and keep the dough refrigerated, or it can be frozen for up to 3 months.
When you're ready, preheat the oven to 400°F / 200°C.
Roll out the pastry to about 1/4 inch thick (I err on the side of a bit thinner) and gentry lift into a 10-inch tart pan. Press the pastry into the pan, trim the edges, and prick the bottom with a fork.
Line the bottom of the tart pan with parchment paper and fill it with rice or dried beans or pie weights if you have those.
Place it into the preheated oven, and bake for 15 minutes.
Remove the tart shell from the oven, remove the parchment and weights, and return to bake for another 10 minutes until lightly golden.
Remove the tart pastry from the oven and let it cool while you prepare the quiche ingredients.