The original recipe for the little tartlets with vanilla cream is probably the best kept secrets in Portugal. Currently only three people know the ingredients of the Pastel de Belém.
Because only then may a Pastel de Nata call, if it contains the ingredients of the original recipe. Were invented Pastéis Belém probably two nuns in the monastery of St. Jerome, which is located in the suburb of Belém in Lisbon and now a UNESCO heritage site.
The Pastéis de Belém were baked for a long time behind the monastery walls and sold to the population and were soon famous and popular. A revolution in the early 19th Century were forbidden to the monastery, the continued manufacture and sale.