Place beef cubes in the slow cooker.
Whisk together soy sauce, broth, brown sugar, vinegar, garlic, and ginger.
Pour over beef.
Cover and cook on Low for 6-8 hours until beef is tender.
Remove beef with a slotted spoon.
Stir cornstarch slurry into the pot juices.
Turn to High and cook for 15 mins until sauce thickens.
Toss beef back in the sauce and serve!
