Heat a large skillet over medium-high heat and add a splash of oil. Sear the beef chuck roast for about 4-5 minutes on each side, until deeply browned. Transfer the beef to a slow cooker.

In a bowl, whisk together soy sauce, grated fresh ginger, and minced garlic to create a marinade. Pour this mixture evenly over the seared beef in the slow cooker.

Cover the slow cooker and set it on low heat, cooking for 8 hours until the beef is tender and shreddable.

While the beef cooks, prepare the gochujang slaw by combining shredded cabbage, thinly sliced carrots, and rice vinegar in a mixing bowl. Refrigerate for at least 30 minutes.

Once cooked, shred the beef using two forks and mix it back into the juices in the slow cooker.

Warm tortillas in a skillet for about 30 seconds on each side. Assemble tacos with shredded beef and top with gochujang slaw.

Garnish with avocado slices, pickled onions, or sriracha, if desired.