This beautiful pie is made from filo pastry which can be bought from delicatessens and good supermarkets. Be sure to buy from somewhere with a reasonably fast turnover, as filo becomes brittle and difficult to work with when old. Keep it in the freezer if you are storing it for more than a day or two. The pie is served with two Mexican accompaniments: spicy salsa, a red sauce that keeps for up to three days in the refrigerator, and a purée of avocados called guacamole. The pie requires a 32-cm/12½-inch loose-bottomed tart pan.