BUENOS AIRES (Reuters Life!) - Imagine a dinner party with complete strangers.
That is the concept behind closed-door restaurants, luring adventurous diners from Buenos Aires to Berlin and New York.
Diners at the unofficial eateries have to ask where the venue is when they call to reserve a table for dinner, which is usually served at the chef's home.
"There's the slightly thrilling feeling of eating in some sort of speak-easy, like the cops are going to rumble you any second," said Sophie Duxson, 22, from Australia, tucking into spicy chicken noodles at Cocina Sunae.
Meals can vary widely from upscale to comfort food and the underground restaurants also offer aspiring or entrepreneurial cooks the chance to experiment with new recipes or share a more unusual cuisine with adventurous foodies.
Asian-American Christina Sunae started her closed-door restaurant at her house on a quiet residential street because she missed home-cooked Asian food, which is difficult to find in Argentina.
In her converted garage, she serves a four-course dinner and wine for about $30 per person.
"I invited friends for my first dinner and that's how it spread," Sunae said in the simple white-washed dining room dotted with candle-lit tables.
Many chefs like Dan Perlman, who cooks at Casa SaltShaker in Buenos Aires, got fed up of the restaurant industry's 12-14 hour days. Casa SaltShaker's menu changes every week, and ranges from tequila soup to seaweed caviar.
The closed-door eateries, which have been popular in Argentina for years, are also a way for entrepreneurial chefs to make money cooking without the commitment or start-up costs of running a restaurant.
"The whole London and New York scenes are burgeoning and were near non-existent just two to three years ago," Perlman said.
One such "supper club" in London is run by James Ramsden, who hosts dinners for 20 once a fortnight at his apartment.
"It is quite surreal looking around your flat and seeing a bunch of unfamiliar faces," said Ramsden, who writes the British food blog "Larder Lout".
The vast majority of his guests are polite and gracious, but some arrive expecting restaurant service, he said.
"They're missing the point in supper clubs, which are about conviviality and a unique dining experience. If you want a restaurant experience, go to a restaurant."
Costa Kalogiros, who hosts the Shy Chef dinner parties in Berlin, said people sitting at the same table often end up becoming friends and exchanging phone numbers and emails.
"We have from 15 to 20 unknown people of all ages around the table, coming together to have fun and eat decent food," he said.
In the past, closed-door restaurants were almost completely reliant on word of mouth recommendations, but social networking sites like Twitter and Facebook have made them accessible to a broader range of people.
Alejandro and Rosana Langer, who started La Cocina Discreta in Buenos Aires in 2007 after a two-year globe-trot, say their guests range from artists to lawyers to diplomats.
"It's very varied, but they all have something in common -- curiosity."