In 1988, my father, Bruce, sold his restaurant Rose et LeFavour in St. Helena, Calif., and took off to spend his first of several winters in Bangkok. He rented a small house on a dirt street, Soy Pra Atit, just four blocks away from the Bang Lamphu shopping district.
On the hottest days, tired from studying Thai at the language school, he would walk down to a takeout restaurant in that neighborhood where they cooked and sold only one item — gai yang. (The literal translation of gai yang is "cooped chicken" as opposed to gai ban, which means "yard chicken.")
He’d stand in a long line to order and then hang around for 15 to 20 minutes while the chickens grilled over a big charcoal fire. The wait was worth it. Half a large chicken, blistered and juicy, was 18 baht (50 cents), a whole was 30 baht (80 cents), and each order came with a cup of sauce and a large scoop of jasmine rice. He ordered his chicken cleaved into wonderfully irregular bony bits, and that’s how I recommend you do it here.
*Note: If you don’t have bird’s-eye chiles, substitute the hottest chiles you can find — habaneros would be my choice. If you don’t have very hot chiles, this sauce will be too sweet.
Make sure the chiles and garlic are properly minced. Give them a few pounds in a mortar and pestle if you have one, or lay a large chopping knife across the peppers and garlic and press down hard to crush them before mincing.
Heat the sugar and water in a small saucepan over low heat until the sugar dissolves. Add the chiles, garlic, and vinegar and bring the mixture to a simmer. Cook until fragrant, 1 or 2 minutes, then transfer the sauce to dipping bowls to cool before serving.
Toss everything together in a large bowl and set aside. (If you need to work ahead, set aside the herbs and salt to toss in just before you take it to the table.)
Combine the garlic, peppercorns, cilantro, fish sauce, and sugar together in a mortar. Using a pestle, pound into a paste. (If you don’t have a mortar and pestle, crush the garlic and peppercorns with the side of knife, chop the coriander and garlic as finely as you can, and stir well in a bowl. You won’t have a paste, but it’ll be just fine.)
Place the chicken on a baking sheet or in a roasting pan and slash across the breast, thighs, and legs. Rub the spice paste all over the chicken and into the cuts you’ve made. Cover and let marinate at room temperature for at least 1 hour and up to 2 hours, or refrigerate for up to 24 hours. (If refrigerating, return the chicken to room temperature for 30 minutes or so to take the chill off before you cook it.)
Build a medium-sized fire in a charcoal or wood grill/barbecue, or preheat a gas grill to medium. Use a well cured grate and scrub it clean with a wire brush. If you are using charcoal or wood, you want hot embers, not flames.
Butterfly the chicken. Put the chicken skin side down on the grate, laying it flat. Let cook for 5 minutes or so before moving it. After that, flip the chicken every 5 minutes or so to keep it from sticking and to keep from burning the skin. (Because you have a whole butterflied chicken, most of the time on the grill will be spent skin side down. Nonetheless, plan on generally flipping the chicken for 30-40 minutes.) A few black spots in this case are in the spirit of the meal.
If the fat is igniting flames, turn the heat down or move the chicken to a cooler spot on the grill. (You can also douse the flames with a squirt bottle if there’s no room to move the chicken out of the way.) The meat should be firm but with a little give when you poke it with your finger. Look for a reading of 175 degrees on an instant-read thermometer inserted into the thigh. If unsure, cut into a thigh and take a peek. Clear juices running from the spot where you pierce the meat and just beyond pink but opaque flesh through to the joint is what you want.
Transfer the cooked chicken from the grill to a cutting board. Using a cleaver — or your biggest, sharpest knife — chop the whole chicken into a dozen pieces or so. You will be chopping right through the bones. This is a fun but messy job — don an apron and go at it without hesitation. Serve the chopped chicken together with the salad, plenty of rice, and the sauce on the side.