I had given up on finding Cuitlacoche, a delicacy of the Aztecs that's been virtually untapped this far north. For those who don't know it, Cuitlacoche is corn smut: a mossy gray fungus that grows inside corn husks after the rain.   

In Mexico City it's treated like a truffle, stuffed into meats and quesadillas for a springy taste of the earth. Up in Tucson you might see it at a special theme dinner in a gourmet restaurant, but other than that, nuthin'.

But travel down to Tubac and you'll find it any day, hidden inside a gorgeous plate of rolled tacos with red cabbage and smokey chipotle salsa. Elvira's Restaurant works with Mexican distributors to import baggies of the corn smut already peeled off the cobs. The Cuitlacoche is stuffed into the tacos along with shredded chicken, onions and jalapeños, then rolled up and fried in oil.

Rip open one of the tacos with your fingers and you can pick out the little black bits: They taste like mushrooms, with just a hint of raw corn. Life is full of delicious, subtle surprises ...    

Interesting fact: Cuitlacoche is actually one of the restaurant's specialties (aside from their incredible mole): Right now they're running a special chile relleno stuffed with Cuitlacoche and Oaxaca cheese, battered in egg and topped with truffle oil and a basil chipotle portofino sauce. They also sell jars of Cuitlacoche in the gift shop, $12.95 for 325 grams from Old Mexico Gourmet. 

Location: 2221 E. Frontage Road

Phone: 520-398-9421

Hours: 11 a.m. to 9 p.m. Tuesdays through Thursdays, 11 a.m. to 10 p.m. Fridays and Saturdays, 11 a.m. to 3 p.m. Sundays, closed Mondays.

Payment: accepts debit and credit cards

Contact Andi Berlin at aberlin@tucson.com. On Twitter: @AndiBerlin

You can find the Star's digital food writer Andi Berlin at a taqueria near you, taking tiny bites and furiously scribbling into an old notepad.