I had dinner at A Naestu Grosum on Tuesday, which apparently is raw food night. The dinner was decent, although I think I would have preferred something cooked (Iceland isn't exactly known for having an abundance of fresh vegetables). I decided to order the dinner special, which was a (cooked) lentil/eggplant "moussaka", served with three raw salads.
The server was very knowledgeable about veganism and even prepared homemade soy whipped cream to put on my dessert. The only vegan dessert at A Naestu Grosum that I have seen is the barley cake, but raw desserts are said to make an appearance from time to time.