You can thank 17th century Portuguese Catholic monks and their recycling efforts for the Pastel de Natas, or Portuguese custard tarts. To ensure crease-free habits, the monks and nuns used egg white for starching and avoided waste by using the precious yolks in their baking leading to the proliferation of the country’s sweet recipes.
Facing closure after the Liberal Revolution the inhabitants of the Jerónimos Monastery in Lisbon took to selling their own recipe Pasteis de Natas to raise funds. On closure they sold the recipe to the local sugar refinery in Belém whose owners opened the now famous Fábrica de Pastéis de Belem.
With ‘Pastéis de Belem’ trademarked by the Lisbon bakery, the ‘Pasteis de Natas’ was born. The puff pastry must be crisp, the custard a little patchy and burnt looking and purists will top it off with a sprinkling of cinnamon or icing sugar.