Artemisia Cafe on Pleasant Street has started serving dinner, Wednesday through Saturday. The evening service is run by husband and wife team Guy and Heather. You can see photos of the menu below (click to enlarge).
The restaurant wasn’t very busy when I was there, but based on my meal (Muhummara appetizer, Pappardelle with Braised Chicken for a main course followed by Lemon Vanilla Layer Cake) I can’t imagine that will be the case for very long.
Update: According to a PFM reader comment, Heather and Guy are Maine natives who spent time working at restaurants in and around San Francisco including Chez Panisse.