Do not skip the browning step. Searing the beef in sesame oil before the slow cooker builds a caramelized crust that adds a deep, savory flavor to the finished dish that slow cooking alone cannot produce.
Cut the beef into small, uniform pieces so every cube becomes completely tender in the same amount of time.
The combination of ground ginger and fresh minced ginger produces a more layered, complex ginger flavor than either one alone. Ground ginger adds warmth throughout the sauce and fresh ginger adds a bright, aromatic punch.
The sauce will thicken as it cooks. If you want it even thicker, stir a tablespoon of cornstarch mixed with a tablespoon of cold water into the slow cooker in the last 30 minutes.