In a cold, moist, musty cellar in the middle of downtown Bruxelles, workers grow high-quality oyster mushrooms and chicory in coffee grounds: “Every year, millions of tonnes of coffee grounds are produced, which are disposed of as waste,” says Julien Jacquet, CEO of Permafungi. He continues: “It’s crazy when you think how much potential is just thrown away.” It is an ideal growth medium for growing mushrooms.