Making Juicy Grilled Flank Steak Rolls is straightforward if you follow these easy steps:

1. Marinate the Steak: In a bowl, combine soy sauce, olive oil, balsamic vinegar, minced garlic, black pepper, oregano, paprika, and salt. Add the flank steak and ensure it is well-coated. Marinate for at least 30 minutes. For best results, marinate in the fridge for up to 4 hours.
2. Prepare the Grill: Preheat your grill to medium-high heat. Ensure the grates are clean and lightly oiled to prevent sticking.
3. Slice the Steak: After marinating, remove the steak from the marinade and place it on a clean cutting board. Using a sharp knife, slice the steak against the grain into thin strips. Aim for about ½ inch in thickness.
4. Assemble the Rolls: Lay out each steak strip. In the center of each strip, place a few slices of bell pepper, zucchini, and a handful of spinach.
5. Roll Them Up: Starting from one end, tightly roll up each strip of steak to encase the fillings. Secure with toothpicks if needed.
6. Grill the Rolls: Place the steak rolls on the preheated grill and cook for 4-5 minutes on each side or until the steak is medium rare and the vegetables are slightly tender.
7. Check for Doneness: For accurate results, use a meat thermometer. The internal temperature should reach 135°F (57°C) for medium-rare.
8. Rest the Rolls: Once cooked, transfer the rolls to a plate. Let them rest for about 10 minutes. This allows the juices to redistribute for enhanced flavor.
9. Slice into Pieces: Carefully remove the toothpicks, if used, and slice each roll into bite-sized pieces.
10. Garnish and Serve: Sprinkle fresh basil on top of the rolls before serving for an extra burst of flavor and color.

These steps ensure you create delicious Juicy Grilled Flank Steak Rolls effortlessly.