Whisk together soy sauce, lime juice, apple cider vinegar, canola oil, maple syrup, toasted sesame oil, and red pepper flakes in a bowl until the maple syrup is fully dissolved and the ingredients are well combined. This ensures even distribution of flavors. Stir in the freshly grated ginger, minced garlic, and chopped cilantro last—this preserves the brightness of the fresh aromatics and prevents them from breaking down in the acidic base.

Pat the flank steak dry with paper towels, then place it in a resealable bag or shallow container. Pour the marinade from Step 1 over the steak and turn it to coat evenly on all sides. I like to massage the steak gently to work the marinade into the meat—this helps the flavors penetrate more deeply. Seal the bag or cover the container and refrigerate for at least 2 hours, but preferably overnight or up to 24 hours for maximum flavor development. The longer marinating time allows the acid and ginger to tenderize the meat while the aromatics infuse throughout.

Remove the steak from the refrigerator 15-20 minutes before grilling to allow it to come closer to room temperature—this ensures more even cooking. Preheat your grill to high heat (around 450-500°F). Remove the steak from the marinade, allowing excess liquid to drip off, and discard the remaining marinade. Place the steak directly on the hot grill grates and cook for 5-7 minutes per side for medium-rare, depending on thickness and your grill's heat. I prefer to avoid moving the steak too much—let it sear undisturbed on each side to develop a flavorful crust.

Transfer the grilled steak to a cutting board and let it rest for 10 minutes before slicing. This resting period allows the juices to redistribute throughout the meat, keeping each slice tender and juicy rather than dry. Slice the steak against the grain (perpendicular to the muscle fibers) into your desired thickness, then serve immediately.