Tuatua is located in an unassuming hole in the wall (boatshed) on the waterfront under Frank Kitts Park. I have passed by it a number of times without paying it too much attention.
However, on a nice day it is difficult to ignore, and so Dawn and I stopped by for lunch. We were pleasantly surprised and have since been back several times.
This is as close to a "healthy" tasting burger as I have had. This is probably because it more closely resembles a sandwich, with a solid serving of salad leaves, and un-melted cumin cheese on a focaccia bun.