In the most prominent backlash of fast food’s apparent embrace of plant-based meats substitutes, an outraged vegan has filed a class-action against Burger King in the US.

Phillip Williams claims that Burger King's Impossible Whopper isn't truly vegan, as the plant-based patties are prepared on the same grill as beef patties. But Burger King never claimed that the Impossible Whopper was vegan.

“While the Impossible Whopper does not contain meat, it is cooked in the same grill as our beef and chicken,” a spokesperson said in August. “Guests may ask for the Impossible patty to be prepared in the oven; however, since our restaurants have an open kitchen environment, we don't label the product as vegan.”

And on Burger King's website, the nutrition information page for the Impossible lists “egg” as an allergen and notes that, “For guests looking for a meat-free option, a non-grill method of preparation is available upon request”.

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Impossible Burgers and other plant-based “meat” alternatives inherently contain no animal products. If cooked at home, they can easily be prepared vegan. And with the Impossible and Beyond burgers both sold at grocery stores around the country, home cooking may be the ideal way for vegans and vegetarians to consume their plant-based “meats”.

However, those upset at chains like Burger King for preparing plant-based patties next to meat products shouldn't hold their breath for the implementation of a separate grill for vegan and vegetarian meal preparation. The addition of a separate grill at all restaurants would be an enormously expensive venture for large chains like Burger King, which has over 3,000 restaurants in the US alone.

It’s not just hungry vegans

Although much of the excitement around plant-based “meat” alternatives has been from the vegan and vegetarian community, the future-oriented mission of Impossible demands more patience than some have now.

“We expect eventually for Impossible to become the new normal,” Impossible Foods CFO David Lee told Business Insider in September. “Generations from now will look up at their grandmas and say, ‘I can't believe you used to eat meat from an animal. How barbaric, how unnecessary’.”

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But a meatless future doesn't mean a meatless present. Impossible and Beyond have been strategic in partnering with major chains to spread the plant-based gospel, understanding that their products give consumers the opportunity to consume less meat in a largely meat-eating society.

These companies' missions require disrupting how people think about eating plant-based foods. They need to prove that plant-based food can be just as delicious, affordable and accessible as meat-based food. It isn't vegetarians that Impossible and Burger King are trying to win over – it’s meat eaters.

But before Impossible's meatless future is here, vegetarians and vegans can have their plant-based “meat” and eat it too. They might just have to visit a supermarket to do so.

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This article originally appeared on Business Insider.