In a large bowl, whisk together the flours and salt for a light, even base.
Pour in the olive oil and 60 ml (4 tbsp) of the cold water, then work the ingredients together (I used a stand mixer).
Gradually add more water, a little at a time, until the dough comes together. You’re aiming for a soft but not sticky healthy pie base. Be patient, letting each addition of water fully absorb before adding more. Your dough should be soft but not sticky.
Shape the dough into a ball, wrap it in clingfilm, and rest in the fridge for 20–30 minutes. There is no butter, so it won’t firm up like a butter-heavy dough. Roll out the dough on a lightly floured surface until it fits your pan (mine was 28 cm) with a slight overhang.
Press the dough into the pan (no need to grease or line the pan), and trim the edges slightly, leaving some extra to account for shrinking.
The wholegrain spelt pastry is now ready to fill with your favourite toppings. No need to blind bake (read here for more information about this). A quiche will generally take 40 minutes in the oven, on 190℃ (375℉), for the crust to bake beautifully. Read here for more detail about this.