Pastéis de Belém, Lisbon

Pastéis de Belém is the bakery beside Jerónimos Monastery where custard tarts have been made since 1837. Its story begins with monks: convent kitchens used egg whites to starch garments, leaving yolks available for sweets. When Portugal closed its religious houses in 1834, the recipe reached the owners of a sugar refinery and its adjoining shop; they began baking here in 1837.

The business remains with their descendants, while the pastry made at this address keeps the name pastel de Belém. Elsewhere in Portugal, the familiar equivalent is called pastel de nata. The recipe is kept by master pastry cooks and prepared by hand in a closed room known as the secret room.

The bakery says it has remained unchanged since the beginning. This is the pastry treated as the original source of every other Portuguese custard tart.