This is a delightful place for Quesadillas. It's located in front of La Purisima square and les than 50 meters from the church with the same name.
They serve quesadillas with a variety of stews. They also offer this with different tortilla options:
1)Regular soft corn tortilla, the traditional taste of tortilla
2)Fried tortilla
The stews may include: beef, cuitlacoche (corn fungus), pumpkin flower, nopales (cactus), eggs, mushrooms, chicarron (pork skin), cochinita pibil (pork with a typical axiote sauce),potatoes and some others. My favorite one is Cochinita.
The service is usually fast, but sometimes it's very crowded and you may have to wait a little, but it totatlly worth it. They have these very tasty spicy sauces, green and red wich are something you've got to try.
It's not expensive, and if you are visiting Monterrey from outside Mexico, this is a must eat.
The place is not very fancy, just cheap and austere, but the taste is great.
If you are at the right time, you may go to the square and find a street market from the Oaxaca people, they have some nice crafts an desserts, read more