1/3 C. orange juice
1 T. balsamic or red wine vinegar
1 T. onion, finely chopped
3/4 tsp. dried rosemary, crushed
1 lb. Lean steak, suitable for grilling, cut 1 inch thick

Combine first 4 ingredients in a bowl. Place beefsteaks in a plastic bag and add marinade, turning to coat. Close bag securely and marinate in refrigerator 30 minutes or up to 6 hours, turning occasionally. Remove steak from marinade and place on grid over medium coals. Grill 17-22 minutes for rare to medium, turning once. Season with pepper to taste; carve into thin slices.