Mix all the ingredients for the pastry together in a bowl by hand, until the mixture forms a dough. Alternatively, blitz in a food processor for 1 minute until well combined.
Form the pastry into a ball, flatten it slightly and place it between 2 large sheets of greaseproof paper. Thinly roll out the pastry to fit a 25cm (10in) round shallow flan tin (tart pan). Prick the pastry all ove