Francesinha

The francesinha was invented in Porto in the 1950s, credited to Daniel da Silva, a returned emigrant who took the French croque-monsieur and adapted it to what Portugal ate and how much of it. The result is bread, ham, linguiça, fresh sausage and steak layered up, covered entirely in melted cheese, and then flooded on the plate with a hot sauce of tomato, beer and stock whose exact composition every restaurant treats as proprietary - the sauce is what people argue about and what distinguishes one house from another. Chips come with it, often in the sauce, and an egg on top is common. It is enormous, and eating one is a commitment rather than a meal. It is also, unmistakably, a dish designed for people who have been drinking, and Porto is not defensive about that. Vegetarian versions exist and are not the same thing.

What you actually see

• The layers - bread, ham, linguiça, sausage and steak under melted cheese.
• The sauce - tomato, beer and stock, poured hot, with a recipe kept secret per house.
• The scale - a plate that defeats most people, with chips and often an egg.
• The 1950s origin - a croque-monsieur adapted by a returned emigrant.

When to go

Year-round. A meal, and plan to do nothing afterwards. Lunchtime or late evening; every café has its own and locals have strong opinions on which.

Honest expectations

It is very large and very heavy - one is a full day's eating for many people. Extremely rich, salty and fatty. Nothing about it suits anyone avoiding meat, dairy or gluten. Sauce heat and quality vary enormously between places.

Nearby

Cafés across central Porto serve it; the Ribeira and Aliados have concentrations.