Heat 1 tablespoon oil in a 10-inch skillet over medium heat. Add the beef and cook until well browned on both sides until desired doneness, about 10 minutes for medium-rare. Remove the beef from the skillet.
Heat 1 tablespoon butter and the remaining oil in the skillet. Add the mushrooms and cook for 5 minutes or until tender, stirring occasionally. Add the shallot, garlic and rosemary and cook and stir for 30 seconds. Stir in the concentrated broth, water and remaining butter and cook until the butter is melted.
Cut the beef diagonally against the grain into thin slices. Serve the mushroom mixture with the beef.
