Authentic Oaxacan Restaurants?
We were there in 1986, so this info is very dated, but we loved Mi Casita, a 2nd floor place near the Zocalo serving very authentic food (zucchine leaf soup, moles, chicken with almonds), and El Meson, an excellent taqueria just of the Zocalo (best for grilled meat tacos, quesadillas with fresh epazote and cheese, and purslane stew- verdolagas). We did not like El Asador Vasco, which seemed to be very popular , but more Spanish than Mexican.
A good guidebook was Fielding's Mexico, by the Fosters. There must be a current addition. I have heard about a number of places since we were there, like a restaurant on the outskirts of town in a home specializing in seafood from the Isthmus, and another in Teotitlan, a nearby town, featuring Zapotec dishes. These would be well worth checking out, as would the market which has lots of fondas.