In a colorful truck painted with flowers, chef Luis Castillejos serves tlayudas -- a toasted corn tortilla topped with shredded beef, avocado, cheese and hot salsa -- to customers in Mexico City.

He has dubbed his truck Nanixhe, which means "delicious" in the indigenous Zapotec language, and the former accountant proposes to serve traditional food with "a gourmet touch."

But instead of driving around the city to find hungry office workers, his vehicle is stuck in a parking lot along with other food trucks.

While the sidewalks of Mexico City are crowded with small food stands that draw big lunch crowds, it has found little space in its heart for gourmet food trucks, which have become mainstays in other major cities such as New York.

The kitchens-on-wheels are in a legal limbo in the mega-capital, where police chase them out of the streets while lawmakers fail to regulate their businesses, forcing them to huddle in places like parking lots or street fairs.

"We want to work in a legal way," Castillejos said.

- Food trucks on Facebook -

With the help of social media, the food trucks manage to advertise their locations to their loyal customers, publishing pictures of their menus, ranging from sushi to Lebanese kebabs.

"It's something original and there aren't many places to eat something different near the office," said Miguel Mendoza, a 39-year-old accountant feasting on ceviche.

Twitter, Facebook, Periscope and Instagram are "the main engines that drive the business," said Jorge Udelman, a Venezuelan chef with 20 years of experience who parks at drive-in movie theaters, concerts or private parties.

Udelman makes Venezuela's traditional arepas, corn cakes stuffed with all sorts of fillings, in a turquoise van. He doubts that the city government will ever give permits to food trucks.

"It's more interested in votes to stay in power than allowing a nicer offering" for foodies, he said.

When food trucks park on a street, "transit police or a borough authority arrives" to kick them out, said Fernando Reyes, president of Foodtrucks DF, an association that represents dozens of the city's nearly 300 food trucks.

While they now exist in the northwestern border city of Tijuana and the Caribbean resort of Cancun, food trucks cannot operate freely like in other countries, Reyes lamented.

Mostly young entrepreneurs, the "food truckeros" (food truckers) spend between $24,000 to $120,000 to start their businesses.

While such vehicles struggle to find a place in the city, the traditional food stands are everywhere, with their owners admitting that they pay bribes to stay open.

- Dead bill -

Several bills have been proposed in the capital's legislature to allow food trucks to operate as long as their food quality and gas and water tanks are regulated.

Priscila Vera, a former city lawmaker for the conservative National Action Party, said the proposed legislation was killed due to "complicity" between the authorities and leaders of the street food stands.

Critics say the traditional food stands lack sanitary standards, with no running water, boiling oil or water in large cauldrons from the early morning.

In contrast, Reyes said, the food truckers want to work legally and pay taxes, promising high sanitary standards with stainless steel stoves, water tanks and refrigeration.

His association is pushing for legislators to revive the bill to finally give food trucks a place in the capital, home to 20 million hungry people.