Melt the butter with the oil in a skillet.
Add the mushrooms and sauté for 10 minutes over medium heat.
Notes
WHAT TO DRINK WITH THIS CREAM OF MUSHROOM SOUP? A dry white wine with minimal oak aging, such as a Chablis, a Mâcon, or a Sancerre, will pair beautifully with this cream of button mushroom soup, highlighting its delicacy without overpowering it. For a non-alcoholic option, a white tea or a light green tea will add gentle herbal notes that complement the flavors of this dish.