Around the outside of the Mercado de 20 Noviembre, numerous comedors serve cheap, fast and tasty meals. Neither of the two comedors I went to particularly stood out and the menus tend to be pretty similar, so follow your gut — or whichever restauranteur catches your eye first! I tried both the mole coloradito ('coloured' but in this case, reddish coloured), which is made with tomatoes and has a tangy, fruity taste, and the mole negro ('black'), which is smokier, spicier and more chocolatey. You can get a mole with rice or on tacos and with meat for about 40 pesos (just under £2).
Another Oaxacan must-do is a trip to the Pasillo de Carnes Asadas ('the grilled meat corridor') at the Mercado de 20 Noviembre. Now, it took me a couple of visits to actually find the corridor. The market building itself — a light blue building with an entrance on the west side of Calle Cabrera between Aldama and Mina — seemed to be closed whenever I visited (I asked a couple of people but couldn't work out whether this is always the case; one woman explained that 'it's a very old building'), and I didn't realise the pasillo was outside in the street. The rules are thus: pick your comedor; pick your meat (the beef tasajo is a good bet); take the ticket you are given and go to the veg stall to pick out onions, chiles and any other accompaniments you might want; take a seat at the table you are pointed to and order any drinks. The meat is grilled and arrives promptly, with some tortillas and your sides. There is no cutlery so just use your hands. It's delicious, and my veritable feast, including a drink, was about 100 pesos (£4.20).
Then there are the tlayudas: large, crispy, toasted tortillas, folded in half, like a crêpe or a calzone, served with refried beans, Oaxaca cheese, and various other accoutrements. I went to Tlayudas Los Libres on Libres near Murguía, a few blocks east of the Plaza Santo Domingo. It's only open late at night and very popular with the locals. There are a few seats on the street and a bigger eating area inside. I ordered mine with cecina (pork) and it was delicious but huge, and I could only finish half. It cost me 70 pesos for the tlayuda and an agua fresca.
Oaxaca is famous for its chocolate, so try to sample a chocolate con agua (hot chocolate with water) while you are in town — I tried one with cinnamon and one with almond. The nieves from Manolo Nieves (just opposite the Plaza Santo Domingo) also make a great sweet treat. You can try Oaxacan speciality flavours, such as mezcal with tamarind, and the ubiquitous grasshoppers (chapulines), but I stuck to the Oaxacan chocolate, which was delicious.
I had a delicious four-course lunch at La Olla, a pretty restaurant in a pink-and-yellow building on Calle de la Reforma. In the afternoons, they do a very good value menu del día for 115 pesos. The menu changes each day and has different themes depending on the day of the week. Thursday was 'Mexico' themed, and my meal included: a mango salad; a tamalito de chaya; a poblano chile stuffed with cheese and plantain; and a nieve made from jiotilla, a type of cactus. I also got a pineapple agua fresca and a glass of mezcal. The food was all delicious and beautifully presented and it was a very good value meal.
Edit: On my last morning, I decided to go for an early brunch at Casa Oaxaca Café before my long journey back to DF. Casa Oaxaca Café is the more casual spin-off of the Casa Oaxaca restaurant, and it's located in the Reforma district, about a 30-minute uphill walk from the city centre. I had forgotten that because it was Mother's Day, it was likely to be busy and indeed, there were lots of big happy family groups celebrating. As I only needed a table for one, the wait was about 25 minutes, but the hosts were great, bringing out extra chairs and complimentary coffee for those in the queue. The restaurant itself is set around a beautiful central patio, with a leafy tree at its centrepiece. I ordered the brunch oaxaqueño (when in Oaxaca...), which included champurrado (a thick hot drink made with chocolate and maize), freshly squeezed OJ, some pan dulce and enfrijoladas with tasajo beef (tortilla chips, a black-bean sauce, chile, onion and cheese). All for 145 pesos. If you go for breakfast or brunch, especially at the weekends, do try booking.
Oaxaca is the home of mezcal, a distilled drink made from a type of agave plant (tequila is made from a different agave variety), and there are tons of mezcal shops and bars in town. On my first night in town, I stumbled upon In Situ, a mezcaleriía on Calle Morelos, whose owner Ulises literally wrote the book on mezcal. They have over 180 varieties and I had no idea where to start so I followed the standard rule of picking the second cheapest category (agave silvestre, in this case) and asked the bar tender to pick one for me. I ended up with a cuixe, which had a fresh woody taste and was so much nicer than any mezcal I've tried back home. My drink was about 50 pesos, but you can pay a lot more for particularly special varieties.
It took me several attempts to visit Mezcolateca on Calle de la Reforma, but it was worth the wait to visit this shrine to Oaxaca's favourite drink, styled like a New York speakeasy with dark wood interiors and green library lamps. I did one of the tasting menus, sampling three very different varieties of mezcal for 160 pesos. I also learnt a lot about the drink from the friendly and knowledgable bartenders. I couldn't resist buying a small bottle of my favourite variety, although once again, I cursed the small size of my suitcase.
For a fun, if less traditional, experience I went for a cocktail on the rooftop terrace at Mezquite on Calle Vigil, just north of Carranza. I ordered a Mezcal Sour (80 pesos), which I sipped as the sun set over the city. NB: although it was relatively quiet when I was there (around 8 pm), it gets busier later on and they may not let you sit at the prime rooftop real estate if you aren't eating there.
Although a lot of Mexico's best coffee is grown in Oaxaca state, Oaxaca city doesn't quite have DF's third-wave of coffee bars just yet. A good choice for caffeination in the downtown area is Café Brújula, which roasts its own coffee and has two central branches. I went to the Alcalá location, which has a lovely, leafy central courtyard. They don't do hand-brewed filter coffees, so I ordered a macchiato, which was rather good. On another day, I tried their espresso, which was also pretty nice.
Hunting for Café Cofetarika one morning, I went into Café Punta del Cielo, which I thought had replaced the former but which may just have been a couple of doors further down Calle Alcalá. It seems to be a chain but the espresso was actually fine and got me through the morning after a late night watching the UK election results.
Drawn in my the turquoise sign and the promise of 'speciality coffee brew bar', I went into Fika on Calle de la Reforma one day. The menu listed Aeropress-, Chemex- and dripper-brewed coffees, but it seemed that French press was the only method available that day (perhaps only one employee knows how to use the others). I ordered the French press, made with coffee from Veracruz, and took a seat upstairs at the Juliet balcony overlooking the street. It was very hot by the window and it took a while for my coffee to cool down, but it was a good brew: a little chocolatey and robust for such a hot day, perhaps, but flavoursome. The price was the usual 30 pesos.