Make the sauce by whisking 1 cup low-sodium beef broth, ½ cup low-sodium soy sauce, ⅓ cup dark brown sugar, 1 tablespoon sesame oil, and 3 teaspoons minced garlic together in a medium bowl.

Add 1 ½ pounds boneless beef chuck roast cut into ¼-inch strips to a 4-7-quart slow cooker and pour the sauce over, tossing the meat to fully coat it.

Cook on LOW for 2.5-3.5 hours. About an hour before it is done, remove ¼ cup of the sauce and whisk it in a small bowl with 2 tablespoons cornstarch. Slowly stir this back into the slow cooker.

At the final 30 minutes of cook time, add 1 (12-ounce) bag frozen broccoli florets to the slow cooker and stir to incorporate. Cover and cook. This will leave the broccoli as crisp-tender, but if you would like the broccoli to be softer, you can partially thaw it prior to adding it to the slow cooker, or you can add it with 1 hour or 45 minutes left in the cook time.

Garnish with green onions and sesame seeds if desired, and serve with white rice.