“The hardest part is to restore people’s confidence,” said Bong Kwok, 34, one of the restaurant’s founders, who opened Suppa in 2017. “This happened too fast.”

The outbreak was the latest in a string of recent troubles for the restaurant and the city.

Jason Ho, 33, the restaurant’s other founder, described the past few months as “a roller coaster.”

For months last year, the restaurant’s Causeway Bay neighborhood was shrouded in tear gas as street battles raged between antigovernment protesters and riot police officers.

After weeks of recording new cases in the single digits, Hong Kong is experiencing a resurgence in coronavirus cases, linked to travelers and overseas residents from Europe who returned to the city as the pandemic marched across the globe.

The government responded this week by limiting the number of customers that restaurants can serve at one time, banning parties of five or more and requiring a minimum distance between tables. Chief Executive Carrie Lam initially said alcohol sales would be banned in bars and restaurants, but she backed off that proposal after the industry pushed back.

Mr. Kwok and Mr. Ho have been savvy about how to best continue to serve customers amid heightened tensions and changing rules. Their methods for coping could serve as a useful model for restaurateurs in other cities dealing with similar issues.

Suppa, a homonym for “give it a blanch” in Cantonese, rolled out delivery services for the first time in February, a move welcomed by loyal patrons who wanted to enjoy hot pot away from the crowds.