Followers of Marc Vetri's Instagram got an eyeful over the weekend - plenty of beauty shots of assorted pizzas and happy-looking Italian chefs.

Turns out, Vetri was on a quick trip to Rome and Campania with his cookbook collaborator, David Joachim, and cookbook photog Ed Anderson, as they gather material for Vetri's next book, Mastering Pizza. They got a tour from Rome-based journalist and culinary guide Katie Parla.

Rome's stops included Gabriele Bonci's celebrated Bonci pizzeria, which itself generated a bit of coincidental buzz last week after Parla wrote on her blog that Bonci will open pizza al taglio outlets in the United States.

Chicago's West Loop will be the first location this summer, and, she wrote, Philadelphia and New York are also on the list.

(Put down the knife and fork, though. Rick Tasman, president of Bonci's USA expansion, told me by phone that no Philly location had been selected. In fact, he said, Bonci and partners want to open in Chicago as a "proof of concept" before expanding.)

Parla says she "peer-pressured" the crew to visit Campania. "A lot of Neapolitan pizza is pretty lame and it's overrated, which was the experience they had when they visited in the past," she said.

She took them to her favorite spot in Naples, 50 Kalò di Ciro Salvo, where they had five or six pizzas.

After taking in views of Vesuvius, they drove out to Caiazzo, where they feasted on more pizza at Franco Pepe's shrine to la pizza, Pepe in Grani.

Day Three had them back in Rome for such treats as the cacio e pepe pizza at Sbanco.

Vetri and Joachim's manuscript, a follow-up to Mastering Pasta, is due this summer for a summer 2018 release with Ten Speed Press.

Vetri's Instagram showed a photo of Mastering Pasta on sale at a shop at the Rome airport.