After a slightly underwhelming visit to the seafood part of Bolhao market, a late breakfast/early lunch for heading off toward the beach was made easier by Casa Guedes being nearby. Porto seems to have a reputation for sandwiches, others (that I didn't get to try) being the pressed hotdog cachorrinho at Gazela Cachorrinhos da Batalha.
Casa Guedes meanwhile has the pork roll €3.9 plain or €4.9 with melted goats cheese. Online reviews say to get the cheese because it keeps the bread more moist. All I can say is that it was somewhat true, but that the plain could be more moist with a little of the gravy from their serving pan. And i did prefer the simpler flavour of the plain one.
Do yourself a favour and get both. I'd want 2 for myself next time too...