He was behind his wooden cart and charcoal stove and making the beloved snack he has spent 30 years perfecting.
The 74-year-old had been selling his speciality in Tai Hang until last year when he was arrested for unlicensed hawking.
He has had all his equipment confiscated seven times last year. His plight made headlines after his customers rallied round him, but to no avail.
Yet on that recent Saturday, he wasn't trying to make a comeback as a hawker. He was there to share the basics of waffle-making, and his experiences as a hawker, with a class of 12 street food lovers.
The workshop was co-organised by the Wan Chai Street Market Concern Group and the Justice and Peace Commission of the Hong Kong Catholic Diocese.
Ng doesn't have much to his name beyond his trademark product. He sleeps in a knocked-together wooden hut and sends most of his salary to his family on the mainland. He hopes the new classes will earn him HK$800 each, helping him make ends meet.
Patsy Chau Pui-sze, from the Concern Group, said the classes would hopefully help Ng while also sparking discussion about Hong Kong's hawker policies.
"Hawkers would want to make their own living and not rely on welfare, but it seems like society doesn't give them much breathing space," she says.
"Besides, we all miss his egg waffles," adds Chau, who became a regular customer of Ng's when she was still in school.
Ng learned his waffle recipe from his uncle. Back then, eggs were not on the list of ingredients. But he believed that artificial flavours and fragrances were not healthy.
"I don't want to be an irresponsible vendor, so I spent one year experimenting on a new recipe that uses real eggs," Ng recalls.
His sense of dedication to his customers made Ng one of the most popular hawkers in the city. On the busiest day, he sold 400 waffles. Yet his fame could barely keep him afloat financially.
He often got arrested - up to 10 times every year. He needed to pay steep fines.
"Sometimes I will lose all I have earned that month," Ng says.
Rebecca Wong Hiu-yan, a student at Shun Tak Catholic English College in Tin Shui Wai, says hawkers deserve more respect.
"I don't think that the noisy, unhygienic and disorderly image that the government has traditionally bestowed on street vendors reflects the truth," says the 16-year-old, who is studying the culture of hawkers.
There is a need for hawkers, she insists. For example in Tin Shui Wai, street vendors can strike a balance in a market that is monopolised by either Cheung Kong Property or by the Link REIT.
Her teacher Sara Ng Yuet-chung agrees. Street vendors can offer more affordable prices for underprivileged people.
And for tourists as well. Miao Chan, a visitor from Singapore, participated in Ng's workshop. She says hawkers in her country belonged to her grandparents' generation and she could no longer see them on the streets like in Hong Kong. "It is a unique culture. We should keep it alive," Chan says.