Ingredients
1-1/4 cups balsamic vinaigrette4 teaspoons ground mustard2-1/4 teaspoons Worcestershire sauce2 garlic cloves, minced3 beef top sirloin steaks (3/4 inch thick and 1 pound each) 5 medium onions, sliced
Preparation
Whisk together vinaigrette, mustard, Worcestershire sauce and garlic. Pour 1/4 cup into a shallow dish. Add beef and turn to coat. Cover and refrigerate 6 hours or overnight. Cover and refrigerate remaining marinade.
Drain beef, discarding marinade from dish. Grill steaks and onions, covered, over medium heat or broil 4 in. from heat until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°) and onions are tender, 4-7 minutes per side. Drizzle reserved marinade over onions. Cut steak into thin slices; serve with onions.
