Londoners have not always bought their food from the stocked aisles of a supermarket, of course. Once upon a time, they all would have visited street markets where "the bellowing and plunging of the oxen, the bleating of sheep, the grunting and squeaking of pigs, the cries of hawkers … quite confounded the senses", as Charles Dickens put it, in Oliver Twist.
Borough Market, Billingsgate Fish Market, Smithfield and Covent Garden are still part of the city's day-to-day existence, albeit without the squalor of Dickensian times. By injecting creativity and entertainment, markets have been reinventing themselves, with street food playing a big role.
Old Spitalfields Market, one of the finest surviving Victorian market halls in London, is buzzing when I visit - hawkers peddling their wares, delivery boys pushing carts, men and women gathered around tables enjoying their lunch, be it Indian samosas, Philadelphia cheese steak, Thai curry or a British pie, fresh lemonade or a doughnut. Parked under a glass and iron roof, beside beautifully restored red-brick buildings, are a dozen or so food trucks and trailers - with names such as Sud Italia (pizzas), Al Chile (Mexican), Tre Rote (Pasta) - and while not all the fare served here comes from these vehicles, meals on wheels have become especially popular in the British capital since the 2008 financial crisis.
"Trucks serving food were a cheaper option to opening a restaurant in London, where rents are exorbitant," says Philip Bell, the manager of Belpassi Bros, an Italian food truck at Old Spitalfields. "As a result, they became all the rage because people were doing good-quality, home-made-style food at affordable prices."
And with London authorities having set no limit on the number of food trucks, they are popping up in markets across the city.
To the east of Spitalfields, and on the other side of the River Thames, the Southbank Centre Food Market is all about the food; it's like a permanent food festival, and there's not a McDonald's or Starbucks in sight.
"It is about individual offerings and individual vendors who are inspired by the global culinary scene and are creating their own fusion and style of food that is both fast and convenient," says Rob Dyas, the owner of Nazari, a Southbank food truck from which chicken and falafel wraps inspired by Moorish-Spanish cuisine are served.
The market is a vibrant feast for the senses and an eclectic gastronomic display - beautifully decorated cupcakes, stinky cheese, a whole roast hog (like siu yuk), delicate French crepes, glazed Korean chicken, Vietnamese bao, paella that smells of the sea, two large steaming cauldrons of Southern chicken gravy and much more. Since opening in April last year, the market has seen a steady increase in the number of food vendors - there are now about 35, 10 of whom operate from trucks, the rest serving from tented stalls, a rough equivalent of Hong Kong's hawkers (which our government is trying to phase out). Having so much variety and quality in one place makes the market much more appealing than the sterile, cookie-cutter indoor food courts we have to put up with in Hong Kong.
Seeing the appeal of wheels, Dyas and his sister, Victoria, bought a second-hand Peugeot camper van and fitted it with a kitchen, for about £30,000 (HK$335,000) in total. After getting a business licence and insurance, all they had to do was register with their local council (one registration generally covers other council districts) and have an Environmental Health Department officer inspect the vehicle for hygiene, health and safety issues. Once assessed and given a rating (5/5 in their case), they were free to climb into their van and drive to markets that offered them pitches. Unlike their future peers in Hong Kong, they required no food-factory licence and didn't have to install a diesel generator or two large water tanks. They can change their menu at will and didn't need to take part in a version of MasterChef (two stipulations that are causing unease among the Hong Kong hopeful).
By providing the space, electricity and water, councils or private agencies that run and maintain markets in London invite food truckers and tented stallholders to pitch for a fee of between £75 a day and £2,000 a month. Realising the caterers might want to operate at a range of events, market managers are accommodating.
"It's a rolling contract based on a good relationship," says Bell. "When we do private events like weddings, corporate parties or festivals, we just update the management. It gives them the chance to invite some other trader during our absence."
Hong Kong's food truck operators will not have such flexibility, as they will be confined, for four months at a stretch, to government-designated tourist hot spots, a restriction that could, if their product proves unappetising, prove disastrous, but could also make financial sense.
"If you are putting food in an area that is within a compound of a tourist destination, people are going to spend because they are already in there," says Tom Riley, manager of The Duck Truck, which is parked in Old Spitalfields Market seven days a week. "[Potential punters] can't go in and out very easily and I suspect they can't take their own food, so you will always have a captive audience."
But what about the locals?
London's answer is Kerb, a private agency that initiated lunchtime-only (12pm to 2pm) gatherings on weekdays, in prime areas. In Hong Kong, that would be like having six or seven food trucks parked outside the HSBC Building, in Central, to catch the lunchtime crowd.
At a Kerb market a few minutes' walk from King's Cross St Pancras, a major transport hub, stand three food vans and six tents pitched on the pavement. Mexican burritos, Philippine barbecue, Malaysian rendang, Scandinavian smoked trout, brownies, burgers and more are on offer for desk jockeys looking for sustenance. Tempting me more than any other is Yuki Maruko's food truck, Yu Kyu, which serves Japanese tonkatsu.
Hong Kong-born Japanese food trucker Maruko explains the appeal of belonging to Kerb: "It is kind of an invitation-only co-op where like-minded traders are invited to trade in markets set up in Paddington, the Gherkin [30 St Mary Axe], King's Cross and West India Quay. And 95 per cent of our customers are office workers, students and artists."
Members find economic safety in numbers; why would the business crowd queue for Wagamama (a British restaurant chain) when they can savour a wide range of well-prepared fare from a "food court" that springs up daily downstairs from their office?
Having rescued an old St John Ambulance van heading to the scrapyard, Maruko installed two deep-fat fryers, a four-burner hob, a water heater and a hand-washing basin. He has back-up LPG bottles should the electricity provided by Kerb cut out. In one fryer sizzles hot chicken katsu (cutlets), which will be served with rice or in a burger bun, and in the other daigaku imo, the sweet potato fries that are commonly sold outside universities in Japan. Although he looks like a pro, he had never catered before and the food truck was his first experience of the industry. He learnt a lot by joining the Nationwide Caterers Association (NCASS).
"As an NCAAS member, you can get all the information needed to start your business, the documentation required, legal issues, basic requirements needed to trade, allergy policies, insurance policies, certified kitchen equipment, etc," says Maruko. "It's very useful especially if you come from another industry. They conduct many training courses that can easily be done online."
In some respects, the Hong Kong Food Truck Association, which rents out vehicles and helps with the official paperwork, does a similar job to the NCASS, but by providing a loan, the SAR government is also trying to encourage first-time entrepreneurs, even though its HK$300,000 maximum is only half the estimated initial start-up cost.
"The estimated price [in Hong Kong] is too high for someone like me, who came from a dead-end office job," says Richard Makin, who owns Blu Top Ice Cream, a business begun with a similar loan from the British government. "I fear that [the licences] will go to existing restaurateurs who have the capital and who may want to increase their market share."
Makin's truck is the only one at the Saturday-only Druid Street Market; the other 30-odd food vendors operate from tented stalls. The street is closed to traffic on market days and when I visit it is crowded - a couple sitting on the pavement enjoying Louisiana-style grilled oysters; a group of young men and women leaning against a wall, sipping craft beer; a mother and daughter sharing a plate of noodles; tourists biting into Indian wraps as they stroll down the street; a man reading a newspaper with coffee in hand; and two sweaty runners treating themselves to one of Makin's sandwich ice creams.
All his flavours are seasonal. Like those of most traders who operate here, his products are responsibly sourced - dairy from the Lake District, fruit from a small holding in Cheshire and British sugar. His biodegradable and recyclable cutlery, cups and plates don't ever get to see a landfill. (Nothing as sustainable has yet been outlined under the Hong Kong Food Truck Pilot Scheme.)
"For us, it is about taking grassroots food inspired by the working class to a bit more of a refined place," says Makin. "Something you feel very passionate about but wouldn't necessarily be able to make in a restaurant, unless it's gourmet. You want to make it imaginative and affordable without compromising on quality."
By exploring menus and tastes, London's street chefs are imbuing their fare with personality, part of the appeal being to set up a tent or a truck in the wind, rain or sun, to be there for customers who appreciate a hearty meal or a well-made snack. That is something Hong Kong's street hawkers and dai pai dong operators have been doing for decades, treating both locals and tourists.
Food trucks will be a great addition to the Hong Kong scene if their "master chefs" are allowed and encouraged to push the boundaries. The scheme should not simply facilitate the creation of a meal like any other that just happens to be served from a hatch on wheels, which appeared to be the case at the recently concluded Food Truck Festival, at PMQ, in Central. With no kitchen allowed inside, the vans were little more than props.
"Street-food culture originated from Asia and the West modified it," says Maruko. "The Hong Kong government is one of the richest and boasts a surplus budget. Wouldn't it be visionary for its financial secretary [who first proposed food trucks for the city] to extend his generosity to those who have never had the opportunity but have always wanted to, by fully funding the project? It would be a great springboard for innovation and entrepreneurship."
Now that's food for thought.