Naco de vazia selado????

Sitting here planning my autumn Coastal Route assault on Santiago and am looking at a Portuguese sample menu in the comfort of my study, and suddenly the name of a Portuguese delicacy pops up not once but twice. "Naco de Vazia Selado" - the Google Guru knows to tranlate this as a"Sealed Bread Loaf", thank you but not much help. The image option shows pictures of steaks, perhaps a stew, also opting for small chunks of unidentified meat with potatoes, as well as slices of rare cooked beef - so I would hazard a guess that it is a meat dish with some sort of Portuguese twist. What please must this be?