📖 Instructions

1. First, let's get that marinade going! In a medium bowl, whisk together the soy sauce, brown sugar, sesame oil, rice vinegar, minced garlic, grated ginger, gochujang (if you like a kick), and black pepper. Taste it! Adjust the sweetness or spiciness to your liking. That's the beauty of cooking—making it your own.
2. Now, prep the steak. Place the flank steak in a large resealable plastic bag or a shallow dish. Pour the marinade over the steak, making sure it's fully coated. If using a bag, squeeze out any excess air. If using a dish, turn the steak a few times to ensure even coverage.
3. Marinate, marinate, marinate! This is key. Place the bag or dish in the refrigerator and let the steak marinate for at least 4 hours, or even better, overnight. The longer it marinates, the more flavorful and tender it will become. But don't go beyond 24 hours, or the meat might start to break down.
4. When you're ready to cook, remove the steak from the refrigerator and let it sit at room temperature for about 30 minutes. This will help it cook more evenly.
5. While the steak is resting, preheat your grill to high heat. If using a cast-iron skillet, heat it over medium-high heat until it's smoking hot.
6. Take the steak out of the marinade, letting any excess drip off. Don't discard the marinade just yet; we'll use it later! Grill the steak for about 3-5 minutes per side for medium-rare, or longer if you prefer it more well-done. The exact cooking time will depend on the thickness of your steak and the heat of your grill. Keep an eye on it!
7. If using a cast-iron skillet, sear the steak for the same amount of time, flipping it halfway through. Aim for a nice, dark crust on the outside.
8. Once the steak is cooked to your liking, remove it from the grill or skillet and place it on a cutting board. Let it rest for at least 10 minutes before slicing. This allows the juices to redistribute, resulting in a more tender and flavorful steak.
9. While the steak is resting, pour the reserved marinade into a small saucepan and bring it to a simmer over medium heat. Cook for about 5 minutes, or until it thickens slightly. This will kill any bacteria from the raw meat and create a delicious sauce to drizzle over the steak.
10. Slice the steak thinly against the grain. This is super important for flank steak, as it can be tough if sliced incorrectly. Cutting against the grain shortens the muscle fibers, making it much easier to chew.
11. Arrange the sliced steak on a platter and drizzle with the thickened marinade. Garnish with sesame seeds and sliced green onions, if desired. Serve immediately with rice, kimchi, and your favorite Korean side dishes.
12. Okay. So if you want some extra amazing flavor, chop up some garlic and yellow onions and stir fry those in the pan with the marinade for a few minutes. The aroma is fantastic and the sauce will taste even better.