Rice Noodles with Lettuce and Ground Beef Gravy

During my years in Thailand, the Peace Corps headquarters in Bangkok was located at the end of Soi Somprasong 2, a meandering urban lane off Petchaburi Road. About halfway down was a pleasant open-air noodle cafe where my friends Sandi, Dudley, Mary Claire, and I often stopped for a satisfying plate of kwaytiow neua sahp. Since the sauce is a simple gravy made with ground beef, it is a particularly quick and easy noodle dish to make at home. I like to serve the noodles on leaves of bibb, Bo