Step 1

Combine the steak, soy sauce, brown sugar, sesame oil, 1 teaspoon vinegar, the ginger, garlic and pepper in a 6- to 8-quart slow cooker. Toss well to coat and dissolve the sugar. Cover and cook on low for 7 hours.

Step 2

Whisk the cornstarch in a bowl with 1 tablespoon water until smooth.

Step 3

Uncover the slow cooker and stir well to break up any clumps of beef, but not shred the meat.

Step 4

Stir in the cornstarch mixture, then stir in the broccoli. Cover and cook on low until the broccoli is crisp-tender, about 30 minutes.

Step 5

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 sriracha.