You can't find authentic Thai cuisine in St. Louis. As the great Jeffrey Steingarten writes in It Must've Been Something I Ate, "[E]ven some of the simplest Thai flavorings and ingredients and the principles of combining them are alien to the Western palate." So here are the criteria we adopted: Keep diners interested. Don't muck it up with a please-'em-all, half-Thai/half-Chinese menu. And stick to balancing the essences of Thai cuisine: hot, sour, salty, sweet. Ladies and gentlemen, we give you Thai Bu-ree. The choo-chee sauce for the salmon is a gorgeous mélange of red curry paste, coconut milk, lemongrass and kafir lime leaves. And guay teaw lord --a wide rice noodle topped with pork, bean sprouts, tofu, cilantro, mushrooms, scallions and a savory-sweet sauce -- is just another way of saying "OK, now we're interested!"