Korean Tacos with Asian Slaw

In a large bowl, whisk together the vinegar, red pepper, and 2 teaspoons soy sauce. Add the cabbage and carrot and toss to combine. Let sit, tossing occasionally, for 15 minutes or until ready to serve. Meanwhile, in a second bowl, combine the sugar, garlic, ginger, and remaining 2 tablespoons soy sauce. Add the beef and mix to combine. Heat the oil in a large skillet over medium heat. Add the onion and cook, covered, stirring occasionally, until tender, 4 to 5 minutes. Add the beef mixture, increase the heat to medium-high, and cook, breaking it up with a spoon, until cooked through, 4 to 5 minutes. Fill the tortillas with the beef and top with the slaw.