My friend Lesley Tellez, whose charming website The Mija Chronicles details her experiences -- mostly culinary -- in Mexico City, also give a series of food tours around town.

While you are eating -- at taco stands, holes-in-the-wall, cantinas and tortilla shops -- Lesley explains much about the history and culture of Mexican food. While she says her work is geared toward tourists who don't speak Spanish, and as such can be easily confused if not totally confounded about what they are ordering, I recently accompanied her on what she calls a "taco tour." She took us to some old favorites plus a couple of standout places to which I had never been. And even I, who have called Mexico City home since 1990, was absorbed and surprised by some of her anecdotes and information. It occurred to me that, as much as I love the food here, and opinionated as I am about it, I really did not know as much as I thought I did about the origins and traditions of what I put into my mouth.

I had a great time with her and a couple of Australians with gargantuan appetites who were with us. Information about the tours is on her website, but here is a direct link to the appropriate page.