In a mixing bowl, whisk together olive oil, minced garlic, soy sauce, lime juice, black pepper, and cumin until well combined. Pour the marinade over the flank steak in a resealable bag or shallow dish, ensuring it's well coated. Refrigerate for at least 1 hour for flavors to meld (overnight is even better!).

Fire up your grill and set it to medium-high heat, reaching around 400°F (200°C).

Remove the flank steak from the marinade and allow any excess to drip off. Place it on the grill and cook for 5-7 minutes on each side, aiming for medium-rare (135°F/57°C).

Once grilled, remove the steak and let it rest for 5 minutes on a cutting board to allow juices to redistribute.

Slice the steak against the grain into thin strips and arrange them on a platter. Optionally drizzle with any leftover cooked marinade.