The plant-based patty is served with vegan cheese, chipotle mayonnaise, aquafaba mayo, lettuce, tomato and onion. While Honest Burger - which has 26 outlets - is only testing the burger in this central London location, if successful, the meal could roll out further.
Plant Based News attended the press launch of the event, and taste-tested Honest Burger's offering, which costs £10.95 including chips.
Plant Based News tested the Beyond Burger. Subscribe to PBN's YouTube Channel here
Speaking at the launch event, Beyond Meat Executive Chairman, Seth Goldman, joked that previous attempts at meat-free burgers - where the ingredients are simply 'smushed' together to form a dry patty - are a meat industry conspiracy aimed at stopping people going vegan.
He added: "We took a different approach [to making veggie burgers] and looked at the burger from a molecular level. We started with water, then we looked at amino acids and you can get many of the same acids from plants as well as meat.
"The protein and the texture we replicated with yellow peas. Then there is fats, so we used coconut and rapeseed oil, and assembled the constituents using heat and pressure to stitch them together so the burger retains its juiciness."