Mexican food is extremely varied, and even just considering the cuisine of the state of Oaxaca, there is great diversity. The Isthmus of Tehuantepec is where the land thins to the narrowest strip between the Gulf of Mexico and the Pacific Ocean. Here the weather is hot and sultry and the food has its own distinct flavors.
Zandunga restaurant in Oaxaca city serves specialties from the Isthmus region, including some seafood dishes, and a few kinds of mole. You'll also find an impressive list of over 60 types of mezcal. All meals begin with complimentary totopos (the regional tortilla chips) and minilla (spicy fishmeal), and salsa. Then take your pick of items from the menu. Maybe some molotes de platano or garnachas to start, and then the enchiladas with two types of mole for the main course. It's all muy sabroso.
Dinner at Zandunga was fantastic. Located in the historic part of Oaxaca City this restaurant is a must. The flavors are traditional Oaxacan cuisine. Try the garnaches de res, enchiladas de mole negro and ojo de agua cocktail with mezcal.