Spray slow cooker with non-stick cooking spray.
Place beef strips inside slow cooker.
In a medium bowl, mix beef broth, soy sauce, brown sugar, sesame oil, and garlic together. Pour over the beef strips in the slow cooker and cook on low heat for 6-8 hours (the beef will be so tender that it will fall apart when you touch it).
In a small bowl, mix together cornstarch and cold water. Mix in with the beef and liquid that is in the slow cooker. Add broccoli pieces to the slow cooker, put the lid back on, and cook for an additional 30 minutes on high heat.
Stir well and serve over hot cooked rice.
