In 2008, Stefano Callegari invented the trapizzino at 00100, his pizza-by-the-slice joint in Rome’s Testaccio district. The name is a play on words, combining tramezzino (a triangular sandwich) and pizza. Unlike a calzone or panzerotto, the bread for a trapizzino is baked separately, then stuffed with a filling to order. Callegari’s innovation featured thick, triangular pieces of baked dough sliced open and filled with traditional Roman mains such as braised oxtail, tripe in tomato sauce, and chicken with peppers. It wasn’t revolutionary by global standards, but it was novel for Rome. And because it was rooted in traditional flavours and transformed main dishes into quick, portable, affordable snacks, the trapizzino was an immediate hit.

Soon it eclipsed 00100’s pizza slices in popularity, and Callegari began travelling around Italy showcasing his invention. But it wasn’t until recently that the trapizzino had a shop of its own. The appropriately named Trapizzino opened in Piazzale di Ponte Milvio in northern Rome last December.

Shortly afterwards, 00100 was closed and a second Trapizzino duly opened in its place. Numerous fillings sit in containers on a counter around the open kitchen. Classic Roman dishes are still available, but they have been joined by others such as the southern Italy-inspired burrata and anchovy filling and zighinì, a spicy Eritrean stew, a nod to Rome’s East African immigrants and a sign that Rome’s palate is slowly starting to try new flavours – and not just new formats like the trapizzino.
• Via Giovanni Branca 88 (Testaccio), and Piazzale di Ponte Milvio 13

Katie Parla blogs about food at Parla Food