They can scrape your inner cheek with a stick and take some living cells, then they grow millions of the cells in a nutrient solution until there is enough of them to make a burger. I think that technically it is cannibalism but they claim you would still be a vegetarian because no 'being' was killed to make the burger. Not sure I would try it myself.
All I would say is they should add peri peri lemon and herb sauce and halloumi cheese with a sesame seed bun to compliment the burger, and remember all the trimmings, iceberg lettuce and gherkin slice.
