If you only eat three meals in Mexico City, make sure they're at these spots

A breakfast offering at Azul Historico in Mexico City is the molletes tradicionales. Photo / Azul Historico

In the Mexican capital, ancient history is ever-present - there are Aztec ruins in the metro, for Tlaloc's sake - and interacting with the now. Mexico City's food scene is no exception, as chefs including Enrique Olvera earn global applause by serving thoroughly modern cuisine made from ancient ingredients. But for every elegant, multicourse tasting menu, there's a $1 street taco served on a handmade, freshly pressed corn tortilla, dripping with grease and love.

Greet the day like a colonial-era aristocrat at the always-busy Azul Historico in the interior courtyard of the chic Hotel Downtown.

The handsome 17th-century building was once owned by the Counts of Miravalle, who made their fortune mining gold, and it now hosts one of chef Ricardo Muñoz Zurita's three signature Mexico City restaurants serving artfully presented Mexican classics. Amid the trees and columns of the arcaded patio, tuck into dishes such as chilaquiles and molletes - or huevos motuleños (US$5.50), two free-range fried eggs bathed in tomato sauce and served with wedges of fried plantains. Afterward, you're ready to explore the Zocalo and the ruins of the Templo Mayora few blocks away.

Street food goes far beyond the taco in Mexico City. On most corners, you can find a señora grilling up anything from huaraches (sandal-shaped masa boats topped with beans, meat, lettuce and cheese) to tlacoyos (thick, blue-corn tortillas in the shape of a football stuffed with requesón cheese or beans) in the shade of a tarp.

Platillos served at El Huequito in Mexico City. Photo / El Huequito

Each is a delicacy, but I always come back to the trusty taco al pastor, especially the one served at the original El Huequito, a taco stand that dates to 1959. With a name that means "hole in the wall" in English, El Huequito lets you fill up on tacos al pastor, made from delectable bits of marinated pork sheared off a trompo rotisserie and crisped up in pork fat with diced onions on the flat-top grill - a whole plateful for about five bucks. Topped with cilantro, a spritz of lime and a splash of house-made salsa, it's glorious.

After spending more than 15 years turning heritage ingredients into serious haute Mexican cuisine in a hushed, buttoned-up dining room in Polanco, Olvera has shaken things up by moving his flagship restaurant, Pujol, to a lighter, brighter, more casual space.

A dinner offering at Pujol is barbacoa taco, avocado purée, borracha sauce. Photo / Maureen M. Evans

You can still enjoy the same dishes that earned Pujol its spot (No. 20) on the World's 50 Best Restaurants list - including a mole sauce that has been simmering for more than four years - if you can get a reservation. If you can't get a table in the main dining room, try for a spot at the taco bar, which serves a sushi-inspired "taco omakase" tasting menu. The US$95 price includes more than enough chef's-choice tacos to fill you up, each served on tortillas made from different varieties of corn, plus three dessert courses, beer and wine pairings, and a welcome cocktail.