As long as Hong Kong has had streets, people have been selling food in them. In its early days, men and women walked up and down the city’s narrow, hilly lanes hawking seasonal vegetables, salted fish and freshly butchered meat. They advertised their goods by calling out in a sing-song melody – ‘at least one million cries uttered every day,’ according to Reverend J Nacken, a British missionary who described the scene in an 1873 letter.

‘The Chinese generally are early risers,’ he wrote, ‘but the congee hawker has been up an hour or two before sunrise.’ He described how hawkers carried their rice porridge in two boxes hanging from a bamboo pole over their shoulders, each containing a pot heated by a small charcoal fire. ‘You may have pig’s blood congee, fish congee, mulberry root flavoured congee, or barley, or kidney or pork and a variety of other congees.’

These mobile hawkers were joined by little green huts known as dai pai dong in the 1950s. Hundreds of them lined the streets near the wharves and factories that drove the city’s booming economy. These were the places that pioneered the satisfying, high-calorie ‘soy sauce’ Western food that is now a Hong Kong favourite. For many locals, nothing starts the day off quite like a milk tea with a ham and macaroni soup, or maybe a chunky fried Spam sandwich.

By the 1970s, more than 50,000 hawkers thronged the city’s streets. The government decided things had got out of hand. It began to license the hawkers and assign them permanent places to ply their trade. The catch was that their licences couldn’t be transferred. Eventually, the entire hawking trade was expected to die out.

For food hawkers, that happened sooner rather than later. Except for the charcoal-burning sweet potato vendors, and a handful of dai pai dongs, no hawkers are permitted to sell food on the streets of Hong Kong. If you want to sell braised duck liver or stinky tofu, you’ll need to rent a shop space.

A few people flouted the law. For years, a call of, ‘dou fu fa, dou fu fa!’ rang through Yau Yat Chuen in the middle of Kowloon as an old man rode his bicycle around the neighbourhood, selling sweet tofu pudding from a wooden bucket. Every Chinese New Year, the streets were filled with the scent of grilled oysters and curry fishballs as illicit night markets sprang up around Hong Kong.

The old man hasn’t been around for a while. But at least you can still count on the dry autumn breeze to carry that mouthwatering scent of charcoal.