Bifanas are a traditional Portuguese dish originated in Vendas Novas, in the district of Évora, in the Alentejo region. It is a very simple and tasty pork sandwich cooked with garlic and wine. Mustard, hot sauce or mayonnaise are the most common dressings.
Casa das Bifanas, at Praça da Figueira ("Figueira Square"), in Lisbon, is a typical Portuguese sack bar / restaurant, known by locals as "tasca", which serves everyday meals. If you would like to try real Portuguese flavors, make sure you look for places like those!