Rachada Moo Yang is the most authentic Thai restaurant I have been to in Hong Kong. Hell, its the most authentic Thai restaurant I have been to anywhere outside Thailand. The fact that you sit on plastic stools on a humid pavement breathing in traffic fumes helps, as does the chatty clientele of mostly Southeast Asian sex workers (it is just around the corner from the Wanchai girlie bar strip). Its cheap, utterly charming, open 24 hours (!) and does a killer pork satay stick in spicy sauce for HK$12.