If you're looking to experience genuine Lao food, a great find is the newly opened Tamarind, directly facing beautiful Wat Nong temple in the old quarter. Open only during the day, they specialise in tasting platters for sampling a range of Lao foods that you won't see in regular cafes, including original fruit drinks unlike anything else in Luang Prabang. Also worth noting are the traditional Lao style meals that can be ordered a day in advance.  Cool enough, the owners name is Joy who walked us through how to eat the traditional meal with our fingers (I had never met a male named that!)