Last week, I took an excellent Mexican cooking class in Santa Fe - the teacher was the author of some cookbooks in traditional Mexican foods. He focuses on regional Mexican cooking, not the beans-tamales-burritos stuff.
An interesting note he made was that, in much of old Mexican cooking, foods were cooked/grilled/braised separately on heated rocks, then added together at the last minute. As a result, the taste does not "blend" but each item retains its own flavor. I tried this at home with a griddle and found it delicious.
Is anyone else aware of other specific Mexican cooking techniques?