Unlocking the secret of Pastéis de Belém, Portugal's prized tarts

The video explores the secretive production of the pistache de belang, a custard tart considered a national treasure in Portugal. Managed by Prestige Blend, the recipe is known only to a select few family members and chefs, all of whom have signed non-disclosure agreements. The recipe, originating from a 19th-century monastery, is produced in a highly secretive environment. The video also discusses the best ways to enjoy these tarts, often with a sprinkle of cinnamon.

Describe the process of how the chefs work with the secret recipe.

What is the preferred way to enjoy the custard tarts according to the speaker?