The King of Porchetta, and Two Roman Pastas Sitting Down

Halfway through this route you meet a man called Piero, whom everyone in the quarter calls the King of Porchetta. You eat his roast pork standing in his shop, with a cold beer. That stop is the reason to pick this tour over the others. The format alternates between sitting down and walking, which matters more than it sounds: two of the courses are eaten at a table, not on the move, and every tasting comes with wine. More than twenty tastings in all. It starts at Campo de' Fiori, either at a family grocery with a board of more than ten cured meats and cheeses, or at a historic Roman eatery for its speciality, the fried fish fillet, with local wine either way. Then the Tiber, crossed on foot on a 1.5 km walk that does the digestion as much as the sightseeing, with St Peter's in view from the bridge. In Trastevere: supplì al telefono, so called because the mozzarella inside pulls into a string when you break one open. The sit-down stop is an osteria, for amatriciana and cacio e pepe. Both are built on the same three ingredients, guanciale and pecorino and pepper, and the guide explains where the two recipes separate and how Roman cooking differs from the rest of Italy. The last stop is a Trastevere gelateria that has been making organic gelato since 1981. Meeting point: Piazza Farnese 42, on the corner by the pharmacy.