 There's nothing else in this pan. You want to make sure that you're cooking the mushrooms pretty hard. So I'm going to start by kind of dehydrating them in the butter to make sure I get all that moisture out. Common mistake, she says, is cooking too low and slow and not adding enough butter. For example, she added about a quarter pound of butter for a pound of mushrooms. And then add flavor. Too much garlic, too much herbs, too much butter. Just a little bit of salt.