Start by slicing the boneless beef chuck roast into 1-inch strips. This size allows for quick cooking and ensures that the beef remains tender.
In a medium bowl, whisk together the low-sodium beef broth, low-sodium soy sauce, dark brown sugar, sesame oil, and minced garlic. This mixture will be the flavorful base for your beef and broccoli.
Place the sliced beef in the slow cooker, then pour the sauce over the beef. Stir to ensure that all the pieces are well coated.
Cover the slow cooker and set it on low for 6-7 hours or high for 3-4 hours. The longer the beef cooks, the more tender it will become.
About 30 minutes before serving, add the frozen broccoli florets directly to the slow cooker. Stir to combine and cover again to let the broccoli steam and cook through.
In a small bowl, mix the cornstarch with a bit of cold water to create a slurry. Stir this mixture into the slow cooker about 15 minutes before serving to thicken the sauce.
Once the beef is fork-tender and the broccoli is bright green, it’s time to serve. Enjoy your Slow Cooker Beef and Broccoli over a bed of fluffy rice or noodles, and savor the deliciousness.