Mercado Azul: Puesto 14 (Tlacoyos)

Follow the smell of toasted corn past the chili sellers and the stacks of plastic buckets, and you will find Puesto 14 under the blue roof of the market. Marta and her sister pat out tlacoyos by hand on a wide clay comal: thick ovals of fresh masa stuffed with refried beans, fava paste or creamy requesón.

They griddle while you watch, then get piled with tender nopales, raw onion, coriander, a spoon of salsa and a snow of crumbly fresh cheese. Two make a breakfast, three make a lunch. The squash-blossom quesadillas are worth the wait when they are on, and the morning atole is thick, warm and lightly sweet.

Bring small change, grab a stool at the counter and point at what the person next to you is having. Everything here is vegetarian unless you ask for chicharrón on top.