It's adapted from a David Lebovitz recipe.
90g salted butter, cut into pieces
1 tbsp vegetable oil
3 tbsp water
1 tbsp caster sugar
150g plain flour
Preheat oven to 210C.
In a medium-sized ovenproof bowl, combine the butter, oil, water, sugar, and salt.
Place the bowl in the oven for 15 minutes, until the butter is bubbling is starting to brown around the edges.
When done, remove the bowl from oven and add in the flour and stir quickly, until it comes together and forms a ball which pulls away from the sides of the bowl.
Transfer the dough to a 9-inch (23 cm) tart mold with a removable bottom and spread it a bit with a metal spoon.
Once the dough is cool enough to handle, pat it into the shell with the heel of your hand, and use your fingers to press it up the sides of the tart mold. Reserve a small piece of dough, about the size of a raspberry, for patching any cracks that will appear once baked.Prick the dough all over with the tines of a fork, then bake the tart shell in the oven for 15 minutes, or until the dough is golden brown.
Remove from the oven and if there are any sizable cracks, use the bits of reserved dough to fill in and patch them.
Let the shell cool before filling.