Two things to get out of the way:
First, profuse thanks to Tom Sietsema for uncovering this gem.
Second, even if you can't stand a molecule of spicy food, go here and get the kao piak* (chicken soup with homemade noodles) and the rice paste wrap. This will be an astonishing meal that might change your ideas about culinary skills. If you want to add spice, ask for some jeo (dipping sauce) on the side.
If you go, it's important to eat the non-spicy food first, because once you get to the spicy food, you won't be able to taste anything else. I also ordered the goi pa fish* (listed sneakily under 'larb'). This is a very spicy ceviche of shredded tilapia. Excellent preparation with lots of fresh sliced lemongrass. Comes with a basket of sticky rice.
*Do not go by my spelling.