Wipe the mushrooms clean. Usually, it is recommended that you do not wash mushrooms, but I do rinse these very quickly and dry immediately, then set aside on paper towels. It’s your choice. Trim stem ends if necessary.
Sauté over medium heat in the butter for 5 minutes, stirring often, mushrooms should release some of their juice..
Season sparingly with salt and freshly ground pepper., white if you have it.
Add sherry, and let the mushrooms cook over low heat for about fifteen minutes, until the mushrooms have given off most of their juices and absorbed the sherry.
Transfer to a serving dish and serve immediately.