Prepare your toppings and set aside. Combine sriracha, mayonnaise and black pepper until mixed thoroughly.
Preheat the grill to 500°F or preheat your cast iron on the stove. Using a paring knife, cut small slits along the length of the beef franks, marking every 1/2-inch and going about halfway deep. Transfer the franks onto the hot grill or cast iron and cook for about 3-5 minutes, turning occasionally to ensure they’re uniformly cooked.
Open buns on your work surface and place one cooked frank onto each bun. Drizzle each with sriracha mayonnaise, then add cabbage mix, kimchi, scallions, and cilantro. Drizzle sriracha mayonnaise again and sprinkle with furikake on top.
Serve immediately with potato chips or fries.