And one place is the undisputed master of making them. In Belem, just off the waterfront, is the Antiga Confeitaria de Belem - a blue and white-tiled temple to eggs, cream sugar and pastry.

The 170-year-old recipe is a secret, divulged to only three chefs at a time. The result is delicious - perfectly browned, with individualism catered for with sachets of icing sugar and cinnamon. The cafe turns out 16,000 tarts a day, all hand-made on the premises and served warm. Worth a trip to Portugal in themselves. (84-92 rua de Belem, Pasteisdebelem.pt)