The story goes that in the early ‘50s, there was a barman at Porto’s A Regaleira who had worked in France. Compelled to make a local version of the croque monsieur, he took a few slices of leftover roast pork leg, supplemented it with thin linguiça, fresh sausage, and a few slices of ham, put all of this between two “bijou” rolls, topped it with melted cheese and drowned the thing in a subtly spicy sauce. Thus the francesinha, approximately “little French girl,” was born.

These days, the over-the-top sandwich has emerged as a must-eat dish for just about every visitor to Porto, and is available at dozens of restaurants in the city. Typically, it’s served with a thin beef steak bulked out with ingredients that can include mortadella, encased in vast squares of white bread, and is often topped with a fried egg and paired with a nest of French fries. But A Regaleira continues to serve that original, slightly daintier (if this can be said about a francesinha) version, referred to on the menu as Francesinha 1952.

The restaurant underwent a massive renovation in 2018, and unfortunately little is left of the classic Portuguese-style workingman’s cafe where that sandwich was invented. But head to A Regaleira’s basement level, and you’ll find what is almost certainly the world’s largest collection of francesinha-themed art—a collection of paintings and sculptures made by local artists to celebrate the restaurant’s renovation and legacy.