First off, reserve a table. We saw many people turned away from this tiny place. And it's worth the reservation! The prices are very reasonable -- especially for the lunch menu -- and the food is great. I'd suggest trying the mushroom appetizer and the shrimp & eel risotto.
The real perk of this restaurant is the service. The owner takes the time to greet everyone personally (even if you're just waiting outside the door) and explain the menu. He's friendly, warm and genuine, someone who obviously cares that you have the best experience you can.
We loved this place enough to visit it twice on a three-day trip.