The Rebel, though, contains a sustainably-sourced soya patty made in partnership with Dutch alt-butcher The Vegetarian Butcher. Originally called the Impossible Whopper in America thanks to its plant-based supplier Impossible Foods, BK’s vegan burger was introduced to every US Burger King branch last August. But there was a catch: despite the patty, which is made with veggie food company The Vegetarian Butcher, and its Veganuary launch, the Rebel Whopper isn’t vegan, as it contains mayonnaise. Developed in collaboration with The Vegan Society and The Vegetarian Butcher, the vegan-certified Vegan Royale consists of a crispy vegan patty, iceberg lettuce, and vegan mayonnaise between a toasted sesame seed bun. Burger King’s Vegan Royale contains soy, wheat, and gluten. The Vegan Royale is available as a meal and comes with fries and a SlPO44b.