Making Juicy Grilled Flank Steak Rolls can be a fun and fulfilling process. Follow these steps for delicious results:

1. Prepare the Marinade: In a mixing bowl, combine balsamic vinegar, olive oil, minced garlic, dried oregano, salt, and pepper. Whisk until well combined.

2. Marinate the Steak: Place the flank steak in a shallow dish and pour the marinade over it, ensuring the meat is well-coated. Cover and let it marinate for 30 minutes to 2 hours in the refrigerator.

3. Prepare the Filling: In a separate bowl, mix together the fresh spinach, roasted red peppers, and mozzarella cheese. This creates a decadent filling for your steak rolls.

4. Preheat the Grill: Heat your grill to medium-high heat, ensuring it is properly prepped for cooking.

5. Slice the Steak: Once marinated, remove the flank steak from the dish and slice it into thin strips, going against the grain. Aim for about ½ inch thick.

6. Assemble the Rolls: Take a slice of flank steak and place a spoonful of the filling mixture at one end. Carefully roll it up tightly and secure it with a toothpick or kitchen twine. Repeat until all steak slices and filling are used.

7. Grill the Rolls: Place the assembled rolls on the preheated grill, turning periodically. Cook for about 10-15 minutes or until the steak reaches your desired level of doneness.

8. Serve Immediately: Once cooked, remove the rolls from the grill and allow them to rest for a few minutes. This helps the juices redistribute.