In a zip-top bag or shallow dish, combine olive oil, minced garlic, salt, and black pepper. Add flank steak and coat thoroughly. Refrigerate and marinate for at least 1 hour or up to 8 hours.

Preheat grill to medium-high heat. Remove steak from marinade and grill for 4-5 minutes per side, or until desired doneness.

Let the steak rest for 5–10 minutes, then slice thinly against the grain.

In a bowl, mix cherry tomatoes, mozzarella balls, and chopped basil. Drizzle with a little olive oil and season with a pinch of salt.

Arrange steak slices and Caprese salad on a serving platter. Drizzle with balsamic glaze just before serving.