Mexico City (CNN) — Mexico City's love affair with food -- from street-side tacos to warm, fluffy tamales that give off a puff of aromatic steam when released from their husks -- is abiding and all-encompassing, and no trip here would be complete without a thorough exploration of the culinary riches the city has to offer.
At the beating heart of this passion is Mercado de la Merced, the city's largest market and one of its oldest.
Dotted throughout its extensive warrens are delicacies from across Mexico -- a huge variety of tastes and styles, from the straight-up delicious to dishes and ingredients not for the faint-stomached. And who better to provide insight and insider knowledge than a trained chef? Nico García, who also works as a guide for Eat Mexico Culinary Tours, is originally from the city of Xalapa -- making him, as he points out, a Jalapeño -- but has been in Mexico City for nine years and knows the market inside out.
"It's an incredible place that you have to see and experience to truly grasp how massive and varied it is," he says.
The market's colors -- like these Miguelito candy powders -- are striking.
"You can find pretty much anything you can think of and it's the oldest part of the city. The modern market was built in the late 1950s, but Merced has been a very active commercial area since the 1300s, and because of all this, it's one of the best places in the city to find traditional market food."
Tours are done only in small groups, especially on the busy weekends, as it is, first and foremost, a working market, and shoppers and vendors have no time for gawking tourists getting in the way. Basic safety precautions, like keeping wallets, cameras and jewelry unobtrusive, are part of a pre-tour emailed brief.
The combo you never knew you needed
The eating begins in earnest in the banquetón, the large food hall that runs the perimeter of the market. The first stop is at -- given what's to come, the relatively prosaic -- McTeo, a market-stall taqueria that, if looked at charitably, pays homage to the king of fast food, Ronald McDonald.
A less understanding interpretation might see lawyers from the burger giant descend on the market with a cease-and-desist order regarding the liberal use of the mascot to sell tacos, but this doesn't seem to have deterred the stall's cheery workers.
The specialty at Tacos McTeo is adding papas fritas -- French fries -- to their tacos.
Instead, in a cloud of oily steam they relentlessly slice potato after potato directly into a vat of boiling oil to provide the papas fritas -- French fries -- that serve as a carb-y garnish for the delicious carne enchilada tacos with cactus and onion. It's the combination you never knew you needed.
Nico says that on a weekend day, they'll get through three 50-kilo (110 lb) sacks of potatoes, easy.
All in all the tour takes in as many as 11 stops, while also wandering through the market's cavernous, multiple-football-field sized halls, so there's little dawdling. A pit stop for fried tamales -- a specialty of the city -- sees Nico expound on one of the most ubiquitous of Mexican foods.
"A famous chef, Ricardo Muñoz Zurita of the Azul restaurants, once tried to catalog every variation of tamal, throughout the whole country," he says. "He had to give up when he realized that he'd write down one recipe, and the guy next door would tell him, 'yeah, but you can also make it like this,'" indicating just the tiniest change. Unfazed, he eventually published his unfinished research in a cookbook.
Five siblings, one taqueria
Each stop involves one or two bites, but upon reaching Cinco Hermanos, the famed family-run taqueria, it's OK to pause a little longer.
Widely recognized as some of the best tacos in the city, Nico says that the secret comes from the synergy of owning the adjoining butcher's shop -- affording the five siblings the choicest cuts to turn into mouthwatering suadero -- a cut of beef similar to brisket -- longaniza (sausage) or tripe tacos.
Cinco Hermanos is rightfully known as one of the best places to get tacos -- possibly in the entire city.
The meat is confited in a vat of bubbling oil, along with the small, sweet onions habitually served as full stops to the meal. A bunch of pápalo leaves, which are used as palate cleansers, is on hand, self-serve, for customers.
Nico shows us market stalls where men thump down huge knives in quick drumbeat succession into huge cakes of chicharrón prensado -- pressed pork -- deconstructing them once again for gorditas or to be added to salsas or tacos.
Nearby, small samples of mole -- encompassing a huge variety of shades from deep, rich chocolate to bright red, are offered and tasted.
An array of moles is available at Moles Dona Balbi.
A few rows over, an impassive worker methodically -- and rapidly -- shaves the spines off nopales, the ubiquitous prickly pear cactus pads that are sold for less than a peso each.
He strips and preps each in seconds flat. "He makes it look easy, but if I were to try to do that, each one would take at least a couple of minutes," Nico admits.
We are in front of one of the smallest stalls, a mere table top, stacked with old plastic jars and bags, opaque with age and use. Alongside them are open, shallow baskets filled with crickets and tiny orange crustaceans called acociles. This is Señora Edith's pre-Hispanic ingredients, a unique stop in La Merced's vastness.
Señora Edith's is a tiny stall selling pre-Hispanic ingredients such as mosquito larvae, ants and stink bugs.
Nico points out dried mosquito eggs and larvae, alongside dried ants and worms and a bug known as cocopaches -- crispy on the outside but harboring a gooey interior.
Most of these ancient ingredients, vital sources of protein in Mesoamerican diets, are handed over, and following a moment of trepidation, sampled.
Chapulines -- grasshoppers -- are a tasty snack that has survived since pre-Hispanic times. To the right are acociles, tiny shellfish.
Blinking in the bright Mexico City sun, the group exits the building -- one of the market's eight -- through a slim passageway and walks along a narrow, bustling alley.
Stalls selling kitchen utensils line the sides, bookending a battered taco stand, next to which, on an old, worn chopping block cratered through years of use, sits a partially dismembered cow's skull.
Wisps of hair and skin stick to it, and Nico says that while customers can usually choose their cut -- from a dizzying array including cheek, tongue, eyeball and eyelid, brain, snout and sweetbreads -- Sundays are too busy so everyone gets the same -- surtida, a mix of all of the above. He says that on a Sunday, they'll get through six entire heads.
Tacos de cabeza -- beef head tacos -- can be found outside the Nave Mayor, in the road that runs between the market and the meat section.
The tacos de cabeza -- literally, "head tacos" -- are complex in taste and texture, but it takes a certain concentration to ignore the fact that we're eating parts of the animal that, in the US or Europe, would normally be discarded.
Still chewing the last of the sticky, flavorful meat we wander to our next stop, El Pollo, which serves us quesadillas de huitlacoche -- quesadillas served with corn smut, the musty, earthy fungus also known as "Mexican truffle."
It's unique to the country -- elsewhere in the world smut is seen as a disease and farmers will destroy whole fields to rid their crop of the infestation, but here it is actively encouraged.
Huge stacks of fruit and veg
Another wander through the halls ensues, past stacks of limes, avocados and the multicolored hues of Mexico's bountiful and varied vegetable crops. Another aisle is filled with huge sacks stuffed with dried chiles, the air redolent with their smokiness.
Stacks of limes and avocados bring vivid greens to the multicolored hues of the market.
En route through the vegetable section, Nico pauses and hands over a few coins to a woman standing beside a small cart. She hands back a few bulbs of garlic. "Every time I'm on one of these tours, I make sure I find her here. This is the best garlic I know." And he says she sells it for about an eighth of the price of a supermarket.
A basketful of habaneros in the vegetable section of the market.
Another building and, after a warning from Nico about the number of bees flying around the alleys, the group is plunged again into the bustling passageways.
This building, the Mercado de Dulces, is home to a bewildering selection of candies, many made with honey -- hence the bees.
Small candy skulls made of amaranth -- an ancient grain which predates the Hispanic era -- lie stacked alongside other skeleton-themed snacks ahead of the Day of the Dead.
Even then it's not over. We emerge from the market to check out a tortilleria, which churns out dozens of the staple a minute.
The flatbreads are so crucial to the Mexican diet that the government regulates the price -- currently around 17 pesos (90¢) a kilo (2.2 lb). Nico says that the average Mexican eats as much as 55 kg (120 lb) of tortillas a year.
Unusually, this place does its own nixtamalization, the complex processing of corn that allows humans to reap the full nutrition of the grain.
Thousands of tortillas are pressed every day in small tortillerias. The staple is regulated by the government.
Around another corner, a hand-pulled ice cream cart, which offers delicious homemade flavors including horchata, cotija cheese with blackberries, passion fruit and lime sorbet.
We finally stagger into Roldán 37, a restaurant set in a restored mansion atop an old dried chile warehouse, for a restorative tequila and a final quesadillita.
It's an exhausting tour, but one bursting with both flavor and knowledge, not only of its food but the rich culture and history of this fascinating city.