At the Feeding the 5000 food festival in New York City, the first thing people walking by may notice is that all the food is free. It isn’t obvious, though, that all the offerings are made from food waste.

A torte is made with trimmings and peelings from a food distributor; a “quick pickle salad” is made with surplus greens and vegetables. Dan Barber, head chef and co-owner of Manhattan’s Michelin-starred Blue Hill, will offer a limited number of cookies made with the almond flour left over when manufacturers make almond oil. Other chefs will also offer cooking demonstrations with food that might otherwise be thrown out.

“I like the idea of changing people’s habits and minds through pleasure and hedonism and enjoyment,” says Barber. “One of the great things about food waste is that if you do it right–in the sense that you talk about it in this context, you avoid the pitfalls of shame on you for leaving food on your plate, or shame on you for ordering that because it’s so wasteful. Instead, you encourage changes in behavior because they’re simply pleasurable.”

Feedback, an environmental organization focused on ending food waste, has hosted similar day-long festivals in Paris, Amsterdam, and other cities in Europe and Australia. They wanted to bring the idea to New York and Washington, D.C., to draw attention to food waste in the U.S.–which leads the world in food waste. The U.S. spends $218 billion a year, and produces massive amounts of climate pollution, growing food that ends up in the trash.

Barber sees the festival as a way to showcase something that chefs already tend to do more than home cooks: making use of leftover scraps. “It’s in our DNA to do that,” he says. At Blue Hill, a ravioli special of braised lamb and vegetables is made with lamb leftover from the last evening’s service and scrap vegetables. It isn’t called “wasted” ravioli, and it goes for $70. But technically, someone might see the ingredients as waste.

“Dishes that speak to bringing the pieces together of what we might consider waste, like offcuts of meat or discarded vegetables, are really the basis of all the great cuisines of the world,” says Barber. “That’s part of a food culture that’s really rich and interconnected. It seems to me like we have a lot of work to do. But the way to do it is through these kinds of things, which really are very enjoyable.”

The festival will be on May 10 at Union Square Park in Manhattan, and May 18 in D.C.