The best place to try real Lao food: you get platters of interesting things to try. Fish barbeque Lao style is great fun and they had lovely gifts of food. Super friendly, not expensive and great drinks! Only open daytimes, but worth a visit.
It's opposite a temple called Wat Nong, lovely location actually, we listened to chanting monks while we ate.
Updates
Now moved to a new riverside spot on the peninsular and does open for evening meals. Also they do a cookery school which I wish I'd done. Food exquisite and reasonable.
Is this your business?