Have you tried Benevolence? It is a small cafe in an alley between the North Market and the Greek Orthodox Church. They have delicious salads and homemade soups along with sandwiches and wonderful baked goods. I love the Grains of the Goddess bread which is filled with sunflower seeds, pumpkins seeds, nuts, and poppy seeds. Their house salad is huge, filling and delcious - overflowing with carrots, cabbage, cucumber, tomato, eggs, swiss cheese, and a great housemade dressing. They also have brunch on Saturdays.
After ordering, have a seat at a long communal table and enjoy the calming atmosphere. They have cute little gift shop items and literature as well.
Check out their web site: http://www.benevolencecafe.com/