A New York City Chinese restaurant has accused a Philadelphia couple of stealing its secret sauce recipe and using it to open Chu Shang Spicy restaurant in Chinatown.

A lawsuit filed last week in U.S. District Court in Brooklyn claims that Jialiang Huang and Meiling Liang contacted the owner of LaoMa MaLaTang in Queens last year and asked to become a franchisee of the restaurant, which specializes in soup and hot pot.

LaoMa MaLaTang's owner, who is not identified by name in the suit, allowed the couple to visit the restaurant. When the owner insisted that they sign nondisclosure and noncompetition agreements, the suit says, they orally promised to comply and gave the owner a $10,000 check as security deposit.

The couple "got access to the plaintiff's kitchen settings, ingredients and plaintiff's unique dishes preparation system," the suit says.

After the couple found a location in Philadelphia, the suit says, the New York restaurateur sent down "a team of professionals" to check it out and give "professional opinions on kitchen renovation and settings."

In July 2017, when Huang again visited LaoMa MaLaTang, he said he had retained an attorney to represent him in the franchise deal. He then was allowed to take photos of the kitchen and ingredients, and the owner taught him the "formula of the Laoma sauce," the suit says.

In August, when the New York restaurateur sent a proposed franchise agreement, Huang and Liang "abandoned the whole deal without good cause," the suit says.

That month, Huang and Liang opened Chu Shang Spicy, 925 Arch St., under the legal name Laoma Philly LLC. The New York restaurant's corporate name is Laoma Spicy LLC.

The suit, also alleging trademark and trade name infringement, seeks unspecified damages.

A woman who answered the phone at Chu Shang Spicy hung up when asked about the lawsuit.

Name disputes among Chinatown restaurants are not uncommon. After Xi'An Famous Food opened at 902 Arch in 2013, it received word from a New York restaurant of the same name. It later was renamed Xi'an Sizzling Woks.

In another case, a settlement was reached three years ago to separate the rival restaurants called Dim Sum Garden. The one at 1020 Race St. uses the Dim Sum Garden name, while the original restaurant, 59 N. 11th St., is called Tom's Dim Sum.