An upscale Manhattan pizzeria backed by a famous dough-tosser shuttered in July — seven months after it opened — because it was a scam, according to an explosive new lawsuit.

La Rossa in Nolita received rave reviews for its margherita pizza when it launched in December, thanks to Stefano Callegari, the Italian chef behind the popular Trapizzino eatery on Orchard Street. Callegari — who rose to fame as the inventor of pizza-dough pocket sandwiches — also runs several popular eateries in Italy.

But La Rossa, a 22-seat Lafayette Street eatery, never made it past summer and was seized by New York City marshals in July for nonpayment of rent. It owed its landlord $46,000 in back rent and more than $44,000 in New York state taxes, court papers say.

Now, one of the eatery’s shareholders has filed suit against La Rossa’s owners, claiming he was defrauded out of half a million dollars through a sham plan to open a chain of La Rossa pizzerias around the world, including in Miami and Dubai. Instead, the money was funneled back to Italy, where the alleged fraudsters are from, according to the Manhattan federal court lawsuit by Italian national Francesco Zanghi.

Callegari is not named as a defendant in the suit, but he could be added at a later date, according to a source close to the case who said Zanghi’s legal team is still investigating the money trail.

Callegari — described on the RomeByMouth website as “a trailblazer” pizza maker — claims to know nothing about the money side of La Rossa because he was a consultant, not an owner.

“It’s an embarrassing situation,” he told The Post by email. “I was brought in as consultant on the project to create the menu and bring my style of pizza to New York. I was naive, I worked for people who ended up fighting among themselves, and in the end they didn’t do what was promised. It’s a shame because I think I did my part.”

Callegari noted that his restaurants in Italy, which include a Trapizzino in Florence, “are still in operation and running very well.” “There was no one who knew how to run the business side,” he said of La Rossa.

The lawsuit claims the dough master’s reputation was used to lure investors, including references to his reputation as the “famous inventor of the ‘trapizzino’ ” — the pizza-dough sandwich.

“With this important deal, the Chef Callegari sells exclusively to the company the use of the pizza products according to the ‘Callegari’s method,’ ” defendant Giuseppe Cavallaro allegedly wrote in May.

Zanghi says he even forked over $165,000 for equipment for the La Rossa Miami — only to discover that “the landlord had gifted the equipment to La Rossa as it was left from the previous tenant,” the lawsuit said.

Zanghi says Cavallaro was his family lawyer when he introduced Zanghi to businessman Piergraziano Ritella and a third defendant, Alessandro Vacca.

The men did not return requests for comment, but they have filed a joint motion to get the case tossed, arguing that they weren’t properly served notice of the complaint, court records show.

Ritella, who is back in Italy, has been denied a visa to return to the United States, according to documents obtained by The Post. His lawyer, Rocco Lamura, did not return calls for comment.

“My client is alleging that he was fraudulently induced by his lawyer and others to invest $500,000 in La Rossa, but that the money was sent back to Italy,” Zanghi’s lawyer, Andrea Natale, told The Post.

‘Catch’ this new steakhouse

A new steakhouse opens this week where #MeToo-plagued Mario Batali’s La Sirena once stood at the Maritime Hotel.

Catch Steak — from the team behind celeb faves Catch Restaurants and Tenjune — will be helmed by chef Michael Vignola, who got his start launching Strip House, which has locations in New York and Las Vegas.

“We are ingredient-focused and health-conscious,” Vignola tells Side Dish. “No one wants 60-ounce steaks anymore. Everyone is working out and health-conscious, wanting a perfect 8- or 12-ounce steak with all the fat and grizzle cut out. Everything is light and shareable.”

Vignola developed the menu with Catch Hospitality Group’s culinary director, John Beatty.

Steaks include American and Japanese Wagyu, Japanese Kobe and other small farm cuts. Offerings include everything from a lean “bone-in cowgirl ribeye” to a soy caramel-glazed Snake River Gold New York Strip. There are also steaks served by the ounce, which will be cooked tabletop on a hot Japanese stone.

Non-meat options include spicy bluefin tuna tartare with Calabrian chili, a four-hour-cured citrus soy egg yolk, and an almond-crusted cauliflower steak with a chili honey drizzle.

Cocktails include Black & Bleu, which boasts a miso-infused vodka, dry vermouth, white soy and truffle blue cheese and olives. The Glass Slipper comes with rye whiskey, palo cortado sherry, Benedictine, absinthe and Cajun salt.

Industrial chic interiors are by The Rockwell Group.

Female chefs join forces for SHARE

We hear … that top female chefs are uniting for A Second Helping of Life, a tasting benefit to support women with ovarian and breast cancer.

The event, to benefit non-profit SHARE, will be held on Sept. 23 at Chelsea Piers. Participating chefs include Butter’s Alex Guarnaschelli; Il Buco’s Donna Lennard; Pearl Oyster Bar’s Rebecca Charles and Sen Sakana’s Mina Newman.

The event will honor Amy Robach of ABC; TV chef Sandra Lee; and Andrea Jung, former Avon CEO — and is being sponsored in part by Barbara Sibley of La Palapa.

It’s the 16th such benefit by the survivor-led group, which offers helplines and support in English and Spanish to women fighting breast and ovarian cancer.