Mushroom steak, mushroom coffee, mushroom supplements . . . You can’t walk more than a few aisles in the grocery store these days without running into some kind of new mushroom product. Fresh white button mushrooms are increasingly joined by specialty varieties like lion’s mane, maitake or oyster mushrooms. There’s sparkling cordyceps tea and chaga coffee boasting a range of health benefits, mushroom chips and even chocolate bars infused with reishi. Well, mushrooms are pretty magical. They’re a hearty, umami-rich meat substitute. They’re a generous source of vitamins, minerals, protein and fiber. And they can grow on waste materials.