We discovered this small vegetarian cafe by accident, and were so impressed that we returned again the next day. Open from about 11 to 6 Monday to Saturday and close to the centre, this cafe usually offers one daily changing choice of starter (eg soup) and main course, both of which in our experience consisted of truly delicious, home cooked vegetarian food, accompanied with good coffee and an irresistible range of superb home baked cakes.
It's a small, clean cafe with friendly staff and a tranquil, stress free atmosphere - a real oasis from the nearby bustling streets. Perhaps because of this, it seemed very popular with local people as well as visiting tourists like us.
Very highly recommended, and all at (especially by Reykjavik standards) a very reasonable price.