The following is from another blog I previously contributed to, the now defunct bangkokfood.blogspot.com. I thought I'd reprint a few of the relevant entries.
Million Dollar Som Tam
The story of our soi would not be complete without a post about our favorite local food stall. We are, what anyone would consider "regulars" at the Isaan food stall which sets up almost directly across from our building. We are not the only ones. When we moved in here, our landlord pointed it out as the "millionaire som tam stand" because the tables are always full, there is always a queue down the soi and sometimes (like last night) you have to wait for upwards of 30 minutes for your food. "You have to be very patient." But it is worth it.
Isaan food, for the uninitiated, is the typical food of the northeastern region of Thailand which is closely connected to Laos, however, it is widely popular in Bangkok and throughout Thailand. I would venture to say that som tam stands are one of the most common food stands to be found on the streets of this city, rivalled only by noodle stands. In some ways, Isaan food is the undiscovered cuisine of Thailand. It is hugely popular here, and even farangs like a sweet watered-down version of som tam, but most of the popular dishes you would never find in a Thai restaurant in the west. Isaan food is intensely spicy, salty and sour and it often includes scary bits of meat like liver and other indiscernable innards, so it is not for the faint of palate, but once you try it it soon becomes a comfort food because of its fresh, savory simplicity. Eating Isaan is one of the cheapest ways to eat well and stands are always packed with motorcycle taxi drivers and construction workers (many of who are from the northeast) as well as more well-to-do Thais (like our landlord).
Som tam is green papaya salad and it is the signature dish of Isaan cuisine. The stands are unmistakable because they always feature a distinctively tall mortar and pestle in which the shredded papaya is pounded with lime, sugar, dried shrimp (or more traditionally fermented land crab) peanuts, tomato, and, of course, chilis. Som tam is an essential dish in Isaan cooking, but it is only the tip of the iceberg. Aside from som tam (which has several variations) Isaan stands specialize in grilled meats (our favorites are the chicken and catfish although the fatty pork is also popular). All the grilled "yaang" dishes come with a rich sauce which includes roasted chilis and tamarind and is cooked down to intensify the flavor. We always order som tam Thai (the kind with shrimp), and grilled something and a third dish which alternates between laap, nam dtok and soup.
Grilled chicken, catfish laap and som tam with sticky rice.
Laap is kind of like a meat salad in that it is ground or chopped meat mixed with lots of herbs and a spicy limey sauce and is served at room temperature. Laap muu (pork) is the most famous and our stand specializes in laap bpet (duck), but my personal favorite is the laap bplaa duk or catfish/snakehead fish laap. "Nam dtok" actually means waterfall in Thai, but at the Isaan stand it is a dish similar to laap, but with more onions and a slightly different sauce, which is supposed to include the drippings from the grilled meat. Sometimes we order Tom Saeb, which is kind of an Isaan take on the classic Tom Yam--it is a spicy soup full of herbs like lemongrass and galangal.
Occasionally, for a change, we opt for "jim jum" alone rather than our usual spread of dishes. Jim jum is like an activity. The soup has a tamarind, chile and herb base which comes in a special clay pot on a clay charcoal burner. You load it up with veggies, glass noodles and the meat of your choice and let it simmer and steam on the table until it's ready. It takes a while to polish off an entire pot with just two people, but that's all right as the broth gets richer and tastier as it simmers. The real challenge lies in getting through the meal without dying from heat exhaustion.
In any case, whatever else we order we always get sticky rice, which is usually served in cute little baskets which keep it moist. Most everything comes with a big plate of fresh raw veggies: cabbage, long beans and lots of basil. The best part about isaan food is that you get to eat it with your hands.