MELISSA BLOCK, host:

Now to a culinary delicacy that's not going to solve any famines but, is revered by chefs in Mexico. Cuitlacoche is a fungus which grows now during the rainy season. When cooked, it turns into a tar-like mush. It may not be pleasing to the eye, but we're assured it is a treat to the tongue.

Monica Ortiz Uribe tracked the journey of this fungus from the cornfields to the dinner tables of Mexico City.

(Soundbite of restaurant)

Ms. RUTH MARTINEZ: (Speaking foreign language)

MONICA ORTIZ URIBE: In the humble barrio of Santo Domingo in southern Mexico City, Ruth Martinez and her husband sit in a modest but busy restaurant, warmly adorned with Mexican artwork. The couple is about to enjoy a chicken breast stuffed with a gunky, black fungus still referred to by its Aztec name, cuitlacoche.

(Soundbite of restaurant)

Ms. MARTINEZ: (Speaking foreign language)

(Soundbite of laughter)

URIBE: To describe the taste of cuitlacoche, Martinez quotes a popular song by the Latin singer Enrique Iglesias: it's a religious experience, she says.

(Soundbite of thunder)

URIBE: From midsummer till the end of October, rain showers on Mexico's maturing cornfields. This is when farmers begin the hunt for cuitlacoche, which they sometimes refer to as El Oro Negro, or The Black Gold.

(Soundbite of farm animals)

URIBE: In a farming village outside Ixtlahuaca, about two hours south of Mexico City, 59-year-old Ezequiel Salinas Ramon stands in his dusty jeans and rancho sombrero at the edge of an endless sea of cornstalks. He's here in hopes of showing a reporter the raw origins of cuitlacoche.

Mr. EZEQUIEL SALINAS RAMON: (Through Translator) We're about to enter the cornfield and see if we can find some cuitlacoche.

(Soundbite of rustling)

URIBE: Salinas pushes through the thick, blade-like leaves, holding out a stick to ward off garden snakes, as he looks left to right, up and down. For every 30 to 40 stalks of corn, he says, maybe one or two are infested with the fungus. But today, we are in luck. Within three minutes of entering the field, Salinas shouts: victory.

Mr. RAMON: (Through Translator) We're in luck. We found one. Here it is.

URIBE: Salinas points to a small, chubby husk split open just enough to expose the bulbous fungus inside.

Mr. RAMON: (Through Translator) This is cuitlacoche. This is how it grows. In the bottom half there are corn kernels, but you can see how the fungus has begun to ferment from the top.

URIBE: A chef in Mexico City later explained that cuitlacoche grows when a drop of rain manages to seep into a crack in the corn husk and begins to rot between the kernels. But for Salinas, cuitlacoche is simply a part of the harvest he's picked every year since he was a boy.

(Soundbite of market)

Unidentified Man #1: (Speaking foreign language)

URIBE: Once collected, farmers take the cuitlacoche in deep plastic buckets to the many markets in Mexico City.

Unidentified Man #1: (Speaking foreign language)

URIBE: Depending on the season, a pound of cuitlacoche can cost anywhere from $1 to $3. From the markets, it's on to homes and restaurants all over the capital. The most popular ways to prepare this delicacy are as a soup or in quesadillas.

Ms. CARMEN RAMIREZ DEGOLLADO (Chef): (Speaking foreign language)

URIBE: Carmen Ramirez Degollado is a renowned chef in Mexico City. She is a traditionalist by heart - from the hand-embroidered apron she wears to the way she prepares her food at her restaurant, El Bajio.

(Soundbite of chopping)

URIBE: Foreigners, she says, have a lot to learn about authentic Mexican food.

Ms. DEGOLLADO: (Through Translator) We have a very fine Mexican cuisine. It's not all about tacos.

URIBE: Ramirez Degollado prepares cuitlacoche simply: with the Mexican herb epazote, onion and chili pepper.

Ms. DEGOLLADO: (Through Translator) The motivation is to preserve our culture. Globalization in these days is a huge threat. People must come and visit our country to truly experience our vast gastronomical landscape.

URIBE: Corn fungus isn't exclusively to Mexico. Only in other places, such as the United States, it's simply thrown out.

For NPR News, I'm Monica Ortiz Uribe in Mexico City. Transcript provided by NPR, Copyright NPR.