Francisco Toledo, an artist of international stature who is widely regarded as Mexico's greatest living artist, is a native son of Oaxaca. As if becoming a great artist isn't enough, he has donated initiative, energy, influence and income to any number of philanthropic projects benefiting the city. He has founded libraries and museums, galleries and workshops. He has purchased and preserved any number of Oaxaca's architectural gems. One of his projects is an outdoor organic market that would delight any natural food enthusiast from Marin County.

Located on land behind an old aqueduct, the mercado, held daily, is no more than a few blocks from any hotel visitors to the city would choose to stay in.

A low doorway, unmarked by any announcement or sign, leads into the market grounds.

Here, a scene similar to farmers' markets everywhere unfolds.

Fresh fruits and vegetables, honey, artisanal cheese, bakery products, lead-free pottery, and more are offered to visitors. Strict rules govern the produce and foods sold. No pesticides or chemical fertilizers are permitted. Foods must be healthy: flour tortillas may not contain lard. No plastic vessels are supposed to be used (although this requirement is difficult to meet).

The main reason for our visit was breakfast. Mine began with a glass of horchata—a sweet drink made from rice, almonds and cinnamon, here spiced up with the red juice of local berries.

She's serving my drink in a regular glass that I was permitted—encouraged—to carry away while exploring the rest of the market. When I was finished, I returned it to her, and she washed it in a (oops—plastic) tub of soapy water and dried it for use by the next customer.

Next it was time for some solid food. What do Mexicans eat for breakfast?

Well, some eat eggs: huevos revueltos, huevos rancheros, huevos divorciados, huevos mexicanos. But most don't. Instead they eat something on or in a tortilla.

Tables everywhere are laden with ingredients. Nopales (cactus), chicken, chayote, wild greens, frijoles, chiles, salsas, moles—the variety is overwhelming and making choices is almost impossible, although overeating isn't.

Tortillas complete the dishes and reduce the need for plates Like everything else here, they're cooked on charcoal braziers.

These were patted out by hand—the ancient, traditional way. I ate a tortitla de huazontle (a sort of tostada topped with stewed amaranth) and chicken mole enchiladas.

We had a long day planned, so I topped everything off with a gourd filled with tejate, the traditional Oaxacan energy drink made from ground corn, cacao seed, mamey seed, and rosita de cacao, a flower that is not from the cacao tree.

Tejate is prepared by making a paste of the ingredients and then adding enough water to make a smooth liquid vaguely similar to chocolate milk topped by curdy foam. I was initially put off by the appearance, but I have to say it's now on my A-list of Mexican foods. It's incredibly tasty and refreshing.

Of course, my sweet tooth wouldn't let me pass up the pastries. These looked as good as anything you'd find in a French patisserie.

The organic market is one of Oaxaca's living art treasures. Don't miss it if you visit the city.