Uncover the slow cooker and let stand for about 5 minutes to thicken. Stir in the remaining 2 teaspoons vinegar. Serve the beef and broccoli over rice and top with scallions, sesame seeds and/or ...

Pour into slow cooker and toss with the beef until combined. Add broccoli and cook, covered, 20 minutes more. Garnish with sesame seeds and green onions and serve over rice.