This deeply flavored brown mushroom sauce is reminiscent of the classic bordelaise sauce but made in a fraction of the time. It's virtually fat-free--another plus. This sauce garnered our highest rating in the Test Kitchens. Try it with beef, lamb, venison, or pork.
Combine wine, shallots, and vinegar in a medium skillet. Bring to a boil; cook until thick (about 3 minutes). Reduce heat to medium. Add broth, Worcestershire, tomato paste, and rosemary; cook 1 minute. Add mushroom mixture; cook 3 minutes, stirring constantly. Stir in mustard.