Traditional cuisines are often damaged by the profusion of assimilated knockoffs that surround them. It's sometimes easier for an ethnic restaurant to just go with the flow, dumb down its food and reap the inevitable rewards as timid diners flock in for the sweet curries, the bland rice and the gummy sesame-everything. But give credit to Pim Fitt, owner of Yummy Yummy Tasty Thai, for avoiding that route and instead sticking with Thai cuisine that's as authentic as you can get without a plane ticket and a passport. From deep-fried spinach leaves, unusual soups and blazing hot Thai curries to the gentler pleasures of rice cakes, coconut ice cream and icy bottles of Singha beer, Fitt serves nothing in her tiny, cozy dining room that isn't exactly the way she knows it should be after half a life spent in Thailand -- and the other half spent teaching the rest of us what the first half tasted like.