A little odd, considering that Wisaijorn works at Bangkok's Chatuchak every weekend. Her restaurant, Green Chili, is at the southern edge of the sprawling market, allowing Wisaijorn the luxury of staying on the perimeter. Some might find her reluctance to plunge in understandable. Chatuchak Market can be a very intimidating place. Sprawling over 27 acres, it is Thailand's, and surely one of the world's, largest public market. Approximately 200,000 shoppers browse through as many as 15,000 stalls every Saturday and Sunday, braving heat and stale air to seek deals on, among other things, fabrics, tailor-made fashion, T-shirts, jeans, shoes, watches, housewares, furniture, handicrafts, ceramics, antiques, collectables, religious items, tchotchkes, pets, art, musical instruments, paintings, sculpture, coins, stamps and, according to the World Wildlife Foundation, illegal endangered species. With the possible exception of high-end electronics, you can buy just about everything at Chatuchak. Including food. Lots of food.

Chatuchak, or Jatujak (locals often call it simply "JJ"), is not primarily about eats. But any place as vast, varied, and crowded as this is going to be full of culinary options-particularly in Bangkok. In this city, quick street food is a way of life. Why cook at home when a great meal can be wokked up on almost every street corner for the equivalent of a buck and a half? And the list of exotic delicacies available at Chatuchak is almost as long as the list of consumer goods. But any food lover's first Chatuchak stop is at Green Chili.

To open every Saturday, Ann Wisaijorn starts cooking on Tuesday. The former Thai Airways PR flack has been running Green Chili for 20 years in the covered food court at Gate 29, beside the Kamphaeng Phet subway stop. The changing array of dishes draws on traditions that are close to home. "My mother cooked every day," she says. "Simple food. I learned a lot of tricks from her-how you solve a problem, fix a mistake. Some of my dishes are my mom's. Some are mine."

Green Chili's client base includes its share of foreigners. (One day it's a table of cooking school instructors from San Francisco, drawn by Wisaijorn's reputation as a master of old-style Thai home cooking.) But Green Chili patrons tend to be local. Like Wisaijorn, some make the trip not because of, but in spite of, the market. "I don't like JJ," says a young woman who identifies herself as Pop. "I just come here to eat at Green Chili. It's a little expensive, though." (She's eating a chicken and lemongrass dish called gai ta krai, for which she paid 40 baht-about $1.30. Expensive is a relative term in Bangkok.)

Wisaijorn says her food is largely a mix of central and southern Thai cuisine, but there's an also an international influence, as in the delicate pork curry dish called Penaeng Moo. "That one is from Indonesia," Wisaijorn admits. "Not Mom."

After lunch at Green Chili, a plunge into the maelstrom. Not everything found in Chatuchak will seem strange or exotic-you can find fries, kebabs and Krispy Kreme doughnuts. But the real fun is doing as locals do. Many of them are lining up for a local favourite known as meung kham. Few snacks so neatly encapsulate the contradictions and complexities of Thai cuisine.

For the casual grazer meung kham (a.k.a. mieng kham) offers levels of surprise. First there are the leaves that wrap these bite-size snacks. Thais call them bai cha pu and they're edible, which is surprise number one. Many bite-size Thai edibles are wrapped in banana leaves, natural packaging not meant to be ingested. Most of those little banana leaf packets are sweet, but just when you get confident that you're buying a little coconut dessert, you'll find a blob of spiced pork instead. With meung kham the confusion persists after you bite in. Appetizer or dessert? The emerald green bundles conceal a mix of seemingly contradictory ingredients-lime, dried shrimp, peanuts, a sweet sugar-cane based sauce, ginger, soy sauce, coconut. It plays out on the palate like a friendly culinary argument. Not to everyone's taste, it's the sort of delicacy that grows on you as you become more accustomed to the unfamiliar traditions of Thai cuisine.

There are enough snacks at Chatuchak to fill an encyclopedia-meung kham, grilled squid or sausage, scrumptious banana pancakes with egg and condensed milk, deep-fried banana and coconut fritters, and khao lam: tubes of sticky rice paste rolled up in bamboo sticks so that the uninitiated would be more likely to classify them as building material than snack food. It's all handy for walking and shopping. But when you're temporarily shopped out and seeking a sit-down meal the options are nearly as varied. And then there's som tam.

Available virtually everywhere street vendors congregate, som tam would make any short list of national Thai dishes. On English menus it's usually called green papaya salad, but few North American restaurants serve it up the way Thais like it-eye-popping, tongue-lolling hot. My first taste came as I watched a batch being prepared at a street cart, and a customer let me have a sample. I chewed, swallowed, smiled, and wondered if it was possible to will the water out of my eyes. That single mouthful was still making me pant minutes later. Eventually I made the happy discovery that you can specify the number of chilies in your som tam. The typical Western palate might find som tam with two chilies agreeably or even aggressively spicy. It's not unusual for Thais to order it with five or six chilies. Phrik song met means two chilies and is a good phrase to memorize, although holding up two fingers usually works. The adventurous might add another chili-phrik sam met.

Som tam is made with a mortar and pestle. The cook dumps sliced tomatoes into the bowl with a number of chilies and adds unripened papaya, cut into slivers, mixed and bruised together with the chilies, dried shrimp, fish sauce, tamarind, lime, perhaps carrot or eggplant or long beans, garlic and sugar. Regional variations are numerous-a common one includes a small salted crab that you might decide is better considered a decorative element. Som tam is often served up with grilled chicken and sticky rice but it's also common to see other meat side dishes like barbecued pork. When not overpoweringly spicy, the dish is wonderfully light and refreshing.

Thai desserts are mostly variations on a theme of coconut-but oh those variations. Saku piak is a bowl of tapioca pearls with sweet corn, red beans or both, flavoured with coconut cream. Another weird-looking treat is made with short rice noodles that have soaked with leaves until they resemble so many little green worms, served with coffee-flavoured coconut milk and shaved ice. These are the kinds of subtle, slightly sweet desserts that can appeal even to those who avoid heavy, sugary cakes and candy, and most go for 20 baht-less than a buck. [Slightly pricier is the traditional mango and sticky rice dessert, which is just as it sounds-a sliced mango served with sticky rice flavoured with coconut milk.

After a brief time in the close quarters and muggy heat of Chatuchak, the search for bargains may take second place to the hunt for hydration. Cold water is available everywhere, as well as yogurt shakes and fruit juices, particularly the juice of fresh Thai oranges-instantly recognizable for its distinctive, sweet flavour. But here, too, there are local options. Check out the man effortlessly pouring long streams of liquid from one pot to another as though playing a huge accordion. He's making a hot coffee and condensed milk beverage, which most of the onlookers will presumably purchase when they're through gawking. Iced tea comes in unexpected flavours here too. Particularly popular is rosella, a type of hibiscus. At Green Chili, Wisaijorn makes her own rosella tea and serves it up in a coconut shell filled with ice.

Out on the border of Chatuchak, Wisaijorn is looking farther afield. She proudly displays packages of germinated brown rice known as gaba-just one of a new line of organic products. With the assistance of her brother Pichet, who's also an assistant commander-in-chief of the Thai army, she's helping to organize a coalition of small organic farmers who will market their products under the Green Chili name in a shop close to Chatuchak. It'll give people a chance to take a little bit of the experience home with them-to a point. Green Chili-and Chatuchak-cannot truly be replicated. All things considered, that's probably for the best. wl