Just say “Xico” and everyone you meet will already know it´s Xico dos Presuntos and a famously good cheap eat in Porto, Portugal.
Standing-only tasca; house-smoked presunto sandwiches, vinho verde, cash only. NO MENU. You´re going there for the presunto so don´t wander too far beyond. You can do that anywhere else.
Expect to pay around €5–10 per person for sandwiches, tremoços, wine in a ceramic bowl. Please try to speak Portuguese.