Truthfully, when I posted my new "Ask Carlos" series a few months ago, I thought I'd be the only one asking the questions. But I underestimated you guys. Turns out there are quite a few people interested in Mexican cheese -- and I am really, really proud to be able to answer your questions. Here's the first installment of Ask Carlos, in which Mexican Cheese expert Carlos Yescas answers two readers' questions. Look for the next installment later this month. Dear Carlos: What Mexican cheese can I use to substitute Mozzarella or Parmesan cheese in lasagna? -- Jorge P. Tocayo: I’ve been married to a Michoacana for over 20 years and have had the fortune of visiting that great state at least once annually. I have come to really appreciate queso cotija, but now that we live in Washington DC, I find it almost impossible to find it - or a suitable replacement for crumbling atop certain dishes. We have to bring back a few kilos (media rueda) every time we return. Do you have any recommendations? Also, do you know the history behind the development and commercialization of this cheese? -- Carlos A. A: Hi Jorge and Carlos: Thanks for your questions. I am going to answer them both together, because they deal with similar topics. First, Jorge. I am happy that you are looking to make Mexican lasagna. Have you heard of budín azteca? It is a great alternative to Italian lasagna that uses tortillas instead of noodles. Mozzarella is a pasta filata or pulled curd cheese. The original mozzarella is made with water buffalo milk and its flavor is very light, but creamy. Quesillo de hebra (otherwise known as queso oaxaca -- I don’t like that name because it was first used dismissively, because the cheese came from a poorer state) is also a pulled curd cheese. It should be a good substitute. However, because quesillo is made with cow’s milk, the acidity makes it melt less uniformly than mozzarella. If you can find a double cream quesillo, you should be able to achieve the same results. In Mexico, I always recommend to chefs to substitute Parmigiano-Reggiano with a good cotija made in Michoacán. And now, Carlos, this also addresses part of your question. Cotija is a very special cheese. The original cotija is made in the Sierra Jalmich, in the mountains of Jalisco and Michoacán. The cheese is then aged in the town of Cotija for a minimum of two months and up to 60 months. The flavor of the cheese depends very much on where in the mountains it was made, but it always has a very distinct mineral, creamy taste. Sometimes the minerality is recognized as saltiness, and that is the reason why cheap commercials copies are just a fresh cheese with a lot of salt. Lactography, my company in Mexico, has really good cotija aged for different amounts of time. We also have a double cream quesillo made organically in Chiapas. They are only available in Mexico right now, but trust me, we are trying to bring these amazing cheeses to the United States. Real cotija has no substitute in terms of flavor, but Carlos, you can use original Parmigiano-Reggiano to approximate the texture and some of the creamy-but-aged flavor of cotija.