Preheat the oven to 200 °C.Rub the butter into the chicken halvesand season with salt and pepper. Place thechicken halves in an oven pan and roastfor 30 minutes or until done.SauceHeat the sugar and 60 ml of thewater in a saucepan until the sugar startsto caramelise. Add the chillies, gingerand remaining water and stir continuouslyto prevent it burning. Add the fish sauce and lime juice and simmer for 1 minutewhile stirring continuously. Keep the saucewarm.Transfer the chicken halves to two platesand drizzle with the sauce. Serve with limewedges, a green salad and rice noodles.