This is definitely a good option for vegetarian visitors, though it is only really half vegetarian despite the name (which, fair enough, actually mentioned "vegetarian AND traditional" food).
Set in a lovely courtyard, with some very nice Oaxacan plates such as mole. A nice buffet, but again, be careful as veggie dishes are right next to meat ones. Service can range from helpfully friendly to quite disinterested, depending on the day.
Recommended for a visit, both for the set menu as well as the buffet, but would be a lot nicer as a dedicated veggie restaurant (which I believe it was at some point).
Cons: Disinterested staff, Only partial emphasis on veggie