Slow Cooker Beef and Broccoli

1 cup beef broth
1/4 cup reduced sodium soy sauce
1/4 cup oyster sauce
1/4 cup brown sugar
1 tablespoon sesame oil
3 cloves garlic, minced
2 pounds boneless beef chuck roast, thinly sliced
2 tablespoons cornstarch
2 heads broccoli, cut into florets

In a medium bowl, whisk together beef broth, soy sauce, oyster sauce, brown sugar, sesame oil and garlic.
Place beef into a 6-qt slow cooker. Add sauce mixture and gently toss to combine. Cover and cook on low heat for 90 minutes.
In a small bowl, whisk together 1/4 cup water and cornstarch.
Stir in cornstarch mixture and broccoli into the slow cooker. Cover and cook on high heat for an additional 30 minutes.
Serve immediately.