In a mixing bowl, combine soy sauce, brown sugar, sesame oil, garlic, ginger, and black pepper to create the marinade.
Add the ground beef to the marinade and mix thoroughly. Let it marinate for at least 30 minutes or up to 2 hours in the refrigerator.
Heat a non-stick skillet over medium-high heat and cook the marinated beef for about 5-7 minutes, stirring occasionally until fully cooked and slightly caramelized.
While the beef cooks, warm the corn tortillas in a separate skillet for 1-2 minutes on each side until they are pliable.
Assemble the tacos by placing a generous amount of cooked beef in each tortilla, followed by shredded cabbage, kimchi, and sliced green onions.
Serve immediately, allowing guests to add more kimchi or additional toppings as desired.