The business expanded as its reputation spread. Chen opened more restaurants. Some of the investors were his customers. He gave a thumbs-up to the business environment in the US, because he "was lucky to get subsidies and low-interest loans".

When the COVID-19 pandemic forced many offline stores to close, Chen's restaurants were among them. Yet the business saw unusual growth online.

"Our sales surged from six to seven times before the pandemic. Some stores sold more than 1,000 bowls a day," he said. "When offline business was struck hard, we turned to online, selling semi-finished rice noodles that take only 2 minutes to heat and eat. This proved popular."

While the Omicron variant is wreaking havoc globally, it has had little impact on his business, he said, as "everybody seems to get used to it, and there is no panic".

Chen said he plans to open 1,000 to 2,000 stores in Canada, Europe, Southeast Asia and first-tier cities in China over the next three to five years to help more people understand Guizhou culture.

"At first, running restaurants was for survival, but then I felt a sense of achievements in entrepreneurship. I became more open, inclusive and made a lot of friends."

Dwight Howard Trudy, a customer from Africa, learned about the restaurant on Facebook. He visited it every week, saying he was interested in the "flavor of Guizhou" and wanted to learn more about the "mysterious place".

Aamir Khan-Kimi, an Indian engineer in San Francisco, said he favors the strong-flavored soup. "The boss is very cute and talkative. We are friends," Khan-Kimi said.

Li Dandan, a visitor from Guizhou, said she was excited to taste the flavor of her hometown during her first time in the US. She drove about 1 hour to get there, bringing her husband and friends.

"The boss often gives us a discount," she said.

Wang Jin in Guiyang contributed to this story.