Discard outer leaves of the lemongrass. Slice thin the bottom 10 cm and mash to a paste in a mortar with pestle. In a shallow bowl, stir together the peanuts, cornmeal, 2 Tablespoon. of the garlic, gingerroot, lemongrass, black pepper, salt and one third cup of the flour. Have ready, in 2 separate shallow bowls, the remaining 1 cup of flour and the buttermilk. Dredge the chicken pieces well in the flour, shaking off the excess, dip them in the buttermilk, letting the excess drip off, and roll them in the peanut mixture, transferring them as they are coated to an oiled shallow baking dish. Bake the chicken, covered tightly with foil, in the middle of a preheated 180ºC oven for 45 minutes, remove the foil carefully and bake the chicken for 20 25 minutes more, or until golden (the chicken will crisp as it cools). In a small saucpan combine the vinegar, sugar, remaining 2.5 Tablespoon. garlic, crushed red chilies, nam pla and the water, bring the mixture to a boil, and simmer it until it is reduced by half. Serve the chicken with the sauce. (Gourmet 0.13186813186813)