In a large mixing bowl, combine the minced garlic, brown sugar, olive oil, Worcestershire sauce, soy sauce, dijon mustard, and sea salt. Whisk everything together until the brown sugar is fully dissolved and the marinade is well blended.
Place the flank steak in a resealable plastic bag or shallow dish. Pour the marinade over the steak, ensuring it’s fully coated. Seal the bag or cover the dish and refrigerate for at least 30 minutes, though a few hours or even overnight will yield even better results.
Preheat your grill or skillet over medium-high heat. If using a grill, make sure the grates are clean and lightly oiled to prevent sticking.
Remove the flank steak from the marinade, allowing any excess to drip off. Place the steak on the hot grill or skillet and cook for about 4-6 minutes on each side, depending on your preference for doneness. Aim for medium-rare to medium for the best flavor and tenderness.
Once cooked to your liking, remove the steak from the heat and let it rest for about 5-10 minutes. This allows the juices to redistribute throughout the meat. Then, slice the steak against the grain into thin strips.
Transfer the sliced steak to a serving platter, and sprinkle with sliced green onions for garnish. Serve immediately with your favorite sides, and watch as everyone digs in!
