When you make a mushroom sauce for steak you use the pan drippings from cooking the steak as part of the sauce. It's an easy and delicious way to add extra flavor!
Sear your steak. Then add butter, fresh rosemary and fresh garlic cloves.
Baste the steak with the melted butter and meat juices. Let the steak rest once it reaches your desired level of doneness.
Add your mushrooms to the pan you used to cook your steak.
Season with salt and pepper, then cook until they have softened and are golden.
Add a splash of red wine & continue cooking.
Serve your coulotte steak with the mushroom sauce. It's so good!