1 12oz or 2 6oz sirloin steaks (can use buffalo)
2 TB olive oil
salt and pepper
1 lb baby bella mushrooms, sliced
2 cloves garlic, minced
1 small onion, finely chopped
1/2 c red wine, preferably Cabernet Sauvignon
1 to 2 TB butter
Saute steak in oil in skillet until desired doneness (2 to 3 minutes per side for medium rare). Remove from heat and tent with foil to keep warm, and to allow juices to return to center.
Meanwhile, in the drippings saute the onion and garlic until translucent. Add mushrooms and cook until moisture is released. Add wine and cook until reduced, about 5 minutes. Add butter and additional salt and pepper, if desired.
Place steak on plate and cover with sauce, or serve sauce on the side.