Pad thai (or the rather cooler phat thai, as the official transliteration has it) is a global ambassador for the glories of Thai food; these simple stir-fried rice noodles are almost certainly one of the best-known examples of Thai cuisine worldwide. Expats claim to use it as a bellwether for the quality of a restaurant: if the kitchen gets the pad thai right, they probably know how to cook.
Quite a claim for a dish that's not neither very Thai nor very traditional – the dish's full name, kway teow pad thai, or "stir-fried rice noodles, Thai-style" hints at its probable southern Chinese origins (kway teow apparently means rice noodles in the Hokkien dialect), and it's thought to have been popularised, andpossibly invented, by Field Marshal Plaek Phibunsongkhram in the 1940s as part of his campaign to foster a sense of national identity.