A typical street restaurant in Bangkok, on the corner of the busy Yaowarat Road and Phadung Dao

Every city in the world is now getting in on the street-food act, but Bangkok is still the best, says John Brunton in his own words and pictures.

Bangkok is a city that never sleeps, a frenetic, anarchic, 24-hour metropolis whose streets are jammed with traffic and people day and night. But those streets are also lined with a non-stop array of tempting food stalls which never seem to close, chaotically set out on the pavement, surrounded by dozens of rickety tables with diners balancing on wobbly stools.

On every corner a cook is bent over a blazing wok, surrounded by a cornucopia of dazzling ingredients – wriggling freshwater prawns, giant lobsters and crabs, freshly-caught seabass, pomfret and grouper fish, plump frogs' legs and snails, clams and exotic crustaceans that look more like sci-fi creatures, myriad exotic vegetables, and delicious tropical fruits ranging from tangy rambutans and lychees to sweet papaya and pungent durian.

I have been travelling all over Asia for many years, eating and photographing street food, but what has always been a local phenomenon is now influencing chefs and restaurant owners all over the world. And if any city deserves the title of capital of street food, then Bangkok has to be the prime contender.

The inhabitants of the Thai capital are mad about food, eating round the clock, and no one thinks twice of braving the traffic jams and crowds to cross from one side of the city to the other just to sample the latest hotspot serving a specialist dish such as 'khao soi' – egg noodles with a mild curry sauce, shallots and pickled cabbage.

There is no stigma attached to street food, so even in the financial district, you'll see sharp-suited businessmen squatting on a stool at a pavement stall next to building workers, both there just for the delicious grub. And as Thais are seriously fastidious about cleanliness, no one should have concerns about the hygiene of eating outside – even the most ramshackle stall along a busy road is spotlessly clean, the products could not be fresher, and even the washing-up is all done in front of you.

Bangkok is a city of markets, and I have always found the best stalls tucked away in different markets. Sampeng Lane is the city's quintessential Chinatown market, and down its narrow streets I discovered a brilliant stall selling 'mamueng nampla wan', a salad of huge green Thai olives and unripe mango, smothered in lethal chillies and dried prawns, while there are always crowds queuing up for stalls specialising in succulent grilled squids, wok-fried fish eggs and barbecued fish wrapped in banana leaf.

In the midst of the maze of textile shops of the murky Pahurat market, I came across an Indian shrine with a small food stall where a Thai lady prepares the best – and spiciest – 'som tam' (green papaya salad) that you will taste in Bangkok. Every chef has their own special recipe for 'som tam', and her secret is to pound in baby crabs to her magic potion. And amid the kaleidoscope of flowers displayed in Pak Khlong market, a stall specialises in chargrilled aubergines, 'Makhuer Phao', that look horribly burnt and smoky on the outside but which are deliciously juicy inside, as the aubergine has been marinated in lime juice and a sour fish sauce.

And at the glitzy Suan Lum night bazaar, they prepare an offbeat variation of the classic 'tom yum moo', cooked Isaan-style from north-east Thailand, using not prawns or chicken as the main ingredient, but pig's intestines, tongue and tail, as well as ribs and lean fillet. Eating out on the street in Bangkok is always a spicy adventure, and the one simple rule I follow is to check out what everyone is eating, and if it looks good, just sit down and order the same.