Combine the broth, soy sauce, brown sugar, sesame oil and garlic in your slow cooker and stir together to combine. Add the uncooked beef pieces and mix until the beef is covered by the liquid.

Turn crock pot temperature to low and cover. Cook for 4 hours (the original recipe says 6 but my beef was perfect after 4 hours, so check to see if yours is done at 4 and if not you can add more time) until the beef is cooked through.

Remove 4 tablespoons of the liquid from your slow cooker to a bowl and stir in 2 tablespoons of cornstarch. Once combined, add the cornstarch mixture back into the slow cooker and mix in thoroughly. Add the frozen broccoli and stir in. Re-cover the slow cooker and cook on low for another half hour.