This is the basic recipe for a dish that allows great variation. Some cooks add a large pinch of powdered turmeric to the paste; others add some fresh lemongrass or a little black pepper. To my mind, the best version comes from a village called Si Saket, in the northeast of Thailand.
Using a pestle and mortar, pound coriander roots, salt, garlic, and peppercorns into a fine paste. Cut chicken in half along the breastbone. Flatten out, wash and dry. Work in the paste, fish sauce, and sugar and leave to marinate for a few hours.
For the sweet chile sauce, pound coriander root, salt, garlic, and chiles into a paste. Combine vinegar, sugar, water, and salt in a pot and bring to the boil. Add paste and stir to dissolve. Simmer sauce until reduced by half, skimming as necessary, then set aside to cool.
Char grill chicken for about 15-20 minutes, turning regularly. Serve with a bowl of the sauce. Eat with raw vegetables, especially cucumber.
Adapted from Thai Food by David Thompson (Ten Speed Press, 2002). Copyright 2002 by David Thompson.
Andrea Reusing is the creator of the restaurant Lantern in Chapel Hill, N.C., and author of the book Cooking in the Moment: A Year of Seasonal Recipes. In this installment of The Key 3, she shares with Lynne Rossetto Kasper the techniques behind three of her favorite recipes: Turnip Soup, Overnight Braised Short Ribs and Tomato Salad.