North Korea's state airline Air Koryo serves passengers just one thing: a burger containing a mystery meat.
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Travellers have questioned whether it's chicken or pork, but the Koryo Burger is always served cold and on a paper doily.
Kim Murphy, an editor at LA Times, shared a photo of the burger on Twitter, with the caption: "North Korea on a bun: Meet the only burger with its own cult following, brought to you by Koryo Airlines".
Journalist Jamie Fullerton wrote for Vice: "The meat was inoffensively dull and, true to the intrigue that surrounds it, even tougher to identify than it was to chew".
But airline reviews website Skytrax revealed that some passengers have enjoyed the in-flight meal.
One traveller wrote: "Their famous Air Koryo burger was a very tasty snack and I would have eaten another."
The temporary eatery in London's Soho opened after it was revealed a quarter of Brits think airplane food is worse than school dinners and hospital food.
The menu on offer at the pop-up, This Is How We Fly, was devised by kiwi chef and restaurateur Peter Gordon to show off the freshness of Air New Zealand's on-board fare.