We tried the Makphet during their happy hour (5:30 PM until 7 PM) and highly recommend their frozen Hibiscus Daiquiri (served blended in a margarita glass) along with their Eggplant Dip (you eat it with sticky rice - it is quite spicy but full of garlic and coriander and therefore REALLY tasty!). The week we were there, they were turning people away every night so reservations are strongly suggested. Also note that they are closed at least one night a week (not sure whether it is Thursday or Friday). A colleague of mine had dinner there with her husband the week before we visited and they both LOVED their experience. All this and apparently for a good cause as well, so definitely a must when in Vientiane.