2 lb flank steak
¼ cup balsamic vinegar
2 Tbsp Worcestershire sauce
2 Tbsp lemon juice
Preheat grill or grill pan to medium-high heat.
Sprinkle steak with salt and pepper. Combine vinegar, Worcestershire sauce and lemon juice. Place steak on a greased grill rack; brush with half of vinegar mixture.
Grill steak, covered, 5 to 6 minutes per side or to desired doneness, basting with vinegar mixture. Let stand 10 minutes before slicing across the grain.
Note: If you have more time, marinate the steak in the vinegar mixture in a zip-top bag 1 hour before grilling for an added boost of flavor. Discard marinade instead of using it as a basting sauce. Use a grill pan instead of an outdoor grill, if desired, and cook the same amount of time.