“We’ve always used other ingredients,” the vendor said, referring to a rule that declares mung bean batter the city’s official jianbing base.

The jianbing rules were first reported on in English by The South China Morning Post.

Xinhua, a state-run Chinese news agency, says that the jianbing’s origins lie in Tianjin, Beijing and Shandong Province. Mr. Song of the catering industry association has said that one of the snack’s two primary strains, the jianbing guozi, has a 600-year history in Tianjin.

People.cn, another state-run news outlet, reported that brick murals and pottery remains show that the Chinese could have been rolling thin pancakes on flat, heated griddles for about five thousand years.

According to Mr. Bing, a jianbing business in New York, legend has it that the snack was invented by a third-century official in Shandong Province who needed to feed an army of wok-less soldiers. The company says that the official’s bright idea — cooking on a copper griddle — drove his army to victory “on a tummy full of bings.”

While the original jianbing is still hugely popular as a street snack, gentrified versions can now be found from Beijing to Brooklyn. It now comes with a quirky range of toppings, complementing the standard ingredients of eggs, scallions, cilantro, chili and sweet sauce and a deep-fried dough wafer.

In New York, for example, Mr. Bing serves bings à la kimchi. And in Hong Kong, the semiautonomous southern Chinese city, the bubble-tea shop ThirsTea offers them with condensed milk and peanut butter.

Fuchsia Dunlop, a London-based cook and food writer who specializes in Chinese cuisine, said that as people in China become more interested in food as a marker of cultural heritage, culinary associations see an opportunity to lure tourists and are moving in some cases to enforce allegiance to traditional recipes.