1Make the slaw: In a medium bowl, toss the coleslaw mix, chopped kimchi, mayonnaise, and half the rice vinegar. Season with a pinch of salt and chill while you cook the beef.
2In a large skillet over medium-high heat, cook the ground beef and diced onion, breaking the beef apart, until browned, 6 to 8 minutes. Drain off excess fat, then stir in the garlic and cook 30 seconds more.
3Stir in the gochujang, brown sugar, soy sauce, remaining rice vinegar, sesame oil, and 1/4 cup water. Simmer, stirring often, until thick and glossy, 5 to 7 minutes. Taste and add more gochujang if you like it spicier.
4Toast the split brioche buns in a dry skillet or under the broiler until golden.
5Pile the Korean BBQ beef onto the bottom buns, top with a generous scoop of kimchi slaw, then finish with sliced green onions and a sprinkle of sesame seeds. Serve warm.
Recipe Lineage
The family tree of this recipe — trace every fork back to the original.