I hadn't seen this post until now, but here goes.
The most famous of the chefs mentioned Ricardo Munoz Zurita, Alicia DeAngeli (El Tajin), Carmen Ramirez Degollado (El Bajio), Enrique Olvera (Pujol, has own classes at http://www.teo.com.mx/english.html) have all offered classes over the years. But don't even dream about it. They all have very successful businesses to run, they travel extensively promoting Mexico's cuisine and do an enormous amount of research and writing, besides promoting charitable causes, WOW.
Read about this years highlights at www.ruthincondechi.blogspot.com.
At the moment no one is doing cooking classes in english, even though that will change in the coming year. Check out http://www.esgamex.com.mx/, if all goes well this centrally located (Colonia Roma - next to Condesa) will have an English program in place.
It's difficult to set up an individual cooking class without a 4 week lead time.
My wife and I are soon going to be in D.F. for a few months, and we are also looking into food-related activities.
On this thread about cooking in Mexico that I posted on the Home Cooking board:
Eat_Nopal suggested trying to take a cooking class with Ricardo Muñoz of the aforementioned Azul y Oro. Does anyone know if he does regular classes?
He also mentioned tours led by local led by local Slow Food members. Has anyone done something like this? I would appreciate any info.
I had a look at the Fundación Herdez link that theabroma posted - they have a tamal class while we are there which looks interesting. Not sure if my Spanish is up to it, though...
The person I mentioned in my earlier post, Ruth in Condechi, is IACP Country Coordinator for Mexico and Leader of the Slow Food Convivium Condesa/Roma in the DF. You can contact her for information about her tours and classes at www.mexicosoulandessence.com. There's no one better. She's bilingual, bicultural, and a marvelously bright, talented, and engaging person.
Ruth in Condechi posts occasionally on this board and also on the Mexico board at eGullet. She lives in the DF, is a long-time Mexican chef, speaks both fluent Spanish and fluent English, and can either offer you a class herself or recommend someone for you. Plus, she's a wealth of knowledge about the city. Contact her!
Can you deal with a class conducted in Spanish? If so, peruse the web site: www.fundacionherdez.com.mx
The only possible drawback is that they do not list classes way far in advance, and sometimes they are like every Tuesday, or Thursday for 3-4 weeks. The classes are excellent, and the kitchen/lecture set up is great. The prices are reasonable.
Otherwise, you may want to contact El Tajin restaurant in Coyoacan or Azul y Oro in the Centro Cultural at UNAM ... they may have classes. There are also several culinary schools in the DF, Claustro de Sor Juana and Marichu being two of them. Google cooking schools in Mexico City, and check it out. You can email them or look at the class lists. Most have a professional program, but many also teach topical classes to non-professionals.