Prepare the Beef:

1. Coat the Beef: In a large bowl, toss the sliced beef with cornstarch until evenly coated.
2. Prepare the Sauce: In a medium bowl, whisk together beef broth, soy sauce, brown sugar, sesame oil, garlic, and ginger.

Assemble and Cook:

3. Add to Slow Cooker: Place the beef in the slow cooker and pour the sauce mixture over the top, ensuring the meat is fully coated.
4. Cook on Low: Cover and cook on low for 4 hours, or until the beef is tender.

Prepare the Broccoli and Sauce:

5. Steam the Broccoli: In the last 30 minutes of cooking, steam the broccoli florets until tender-crisp. Alternatively, add the broccoli to the slow cooker for the last 30 minutes.
6. Thicken the Sauce: In a small bowl, mix 1 tablespoon of cornstarch with 1 tablespoon of water to create a slurry. Stir this into the sauce in the slow cooker and let it cook for an additional 10 minutes to thicken.

Finish and Serve:

7. Combine and Serve: Toss the steamed broccoli with the beef and sauce until well combined. Serve over rice or noodles, garnished with sesame seeds if desired.