Place all the pastry ingredients in a food processor. Process until a rough dough forms, if there are still a lot of dry crumbs left, add a little bit of water (1tbsp at a time) Tip your dough onto a floured surface, roll out to fit the tart tin (22x32cm loose bottomed tart tin). Prick with a fork. Refrigerate 20 minutes. Bake the pastry for 20 minutes in 180c fan forced oven.