"This is a light soup, can be used as a main dish or as a complement to an entree. I kinda made this up a few years ago and having been fiddling with it ever since. You can substitute any type of mushroom you wish or even go for a mix of mushrooms. You can use olive oil instead of butter but I think that olive oil overpowers the taste of the mushrooms.
The celery, onions, and garlic does not kill the flavor of the mushrooms. When you simmer the soup, the mushroom flavor comes to life. Feel free to change this one up and share your experiences and modifications."