30-Minute Grilled Flank Steak
Tender flank steak marinated in balsamic vinegar, brown sugar, and fresh rosemary, then grilled to perfection and topped with a glossy reduced glaze. The diamond scoring technique ensures maximum flavor penetration while keeping the meat juicy. Perfect for summer barbecues or elegant dinner parties when you want restaurant-quality results at home. The sweet-tangy glaze balances the beef's richness beautifully.
Ingredients
- 2 beef flank steaks (1 lb each)
- ⅓ cup balsamic vinegar
- 2 tablespoons brown sugar, packed
- 1 tablespoon fresh rosemary leaves, chopped
- 1 teaspoon dried rosemary leaves
- 3 cloves garlic, finely chopped
- ½ teaspoon salt
- ½ teaspoon pepper
- ½ cup reduced-sodium beef broth
- 2 teaspoons cornstarch
- canola oil, for brushing grill
Instructions
- 1
Trim fat from beef and score diamond pattern 1/2 inch apart, 1/8 inch deep on both sides
- 2
Mix vinegar, brown sugar, rosemary, garlic, salt and pepper in small bowl
- 3
Place beef in shallow glass dish and pour marinade evenly over beef
- 4
Cover and refrigerate at least 4 hours but no longer than 24 hours, turning occasionally
- 5
Heat grill and brush rack with canola oil
- 6
Remove beef from marinade and reserve marinade
- 7
Place beef on grill over medium heat and cover
- 8
Cook about 12 minutes for medium doneness, turning after 6 minutes
- 9
Heat reserved marinade in saucepan over medium-high heat until boiling
- 10
Boil 3 to 4 minutes or until reduced by half
- 11
Mix broth and cornstarch in small bowl
- 12
Stir broth mixture into marinade and cook about 2 minutes until thickened
- 13
Place beef on cutting board and cut diagonally into thin slices
- 14
Place slices on serving platter and spoon sauce over beef
Tips
Score the meat in a diamond pattern to break down tough fibers and allow marinade to penetrate deeper for maximum flavor and tenderness.
Reserve some unmarinated sauce separately if serving to guests with food safety concerns about using marinade that touched raw meat.
Let the sliced steak rest 5 minutes after cutting to redistribute juices before serving with the warm glaze.
Good to Know
Refrigerate cooked steak up to 3 days. Store sauce separately.
Marinate steak up to 24 hours ahead. Sauce can be made 2 days ahead and reheated.
Serve immediately while steak is warm and sauce is hot for best flavor and texture.
Common Mistakes
Don't skip scoring the meat to avoid tough, chewy texture.
Don't overcook past medium or steak becomes tough and dry.
Boil marinade thoroughly to avoid food safety issues when using as sauce.
Substitutions
FAQ
Can I use a different cut of beef?
Yes, skirt steak or hanger steak work well with similar cooking times. Avoid thick cuts like ribeye as they need different techniques.
What if I don't have a grill?
Use a grill pan or cast iron skillet over medium-high heat. Cook 4-5 minutes per side for medium doneness.
How long does the cooked steak keep?
Refrigerate up to 3 days. Reheat gently to avoid overcooking. Best served fresh for optimal texture and flavor.