The atmosphere at Ploy Thai, a newish restaurant on the corner of Elmhurst Avenue and Broadway in Queens, seems promising in its authenticity; upon entering for the first time we were pleased to find a few tables of Thai families, a specials board written completely in Thai and karaoke of girl band Girly Berry playing on a flat screen TV. We ordered two of the specials: yum pla duk fu, or fluffy catfish salad and......