Crock-Pot Beef and Broccoli

3 lbs beef (roast or steak), cut into bite-size pieces
9 (or more) garlic cloves, chopped
1 1/2 cups soy sauce
3 cups beef broth or water
1/3 cup brown sugar
3 TBSP sesame oil
2 lbs frozen broccoli florets

Combine everything except the broccoli in a 6 quart (or larger) Crock-Pot. Cook on low for 4 hours, then add the broccoli and cook for 1 more hour. Serve over rice. Great with sriracha sauce.