01 -
In a mixing bowl, whisk together balsamic vinegar, olive oil, Dijon mustard, honey, minced garlic, salt, and black pepper until fully emulsified.
02 -
Place flank steak in a shallow dish or resealable plastic bag. Pour half of the marinade over the steak, ensuring full coverage. Cover and refrigerate for at least 8 hours or overnight.
03 -
Preheat grill to medium-high heat, approximately 400°F.
04 -
Remove steak from marinade and let excess drip off. Grill steak for 3 to 5 minutes per side, or until medium-rare or preferred level of doneness is reached. Transfer to a cutting board and allow steak to rest for 5 minutes.
05 -
Place cherry or grape tomatoes on the grill and cook for 3 to 5 minutes, turning occasionally, until lightly charred and blistered.
06 -
Slice flank steak against the grain into thin strips. Arrange steak on a serving platter and top with grilled tomatoes, diced mozzarella, and basil. Drizzle with remaining marinade and serve immediately.