Place the flank steak in a bowl with the cornstarch and toss to coat.
Add the flank steak to your slow cooker.
To the slow cooker add your sesame oil, garlic, ginger, soy sauce, brown sugar, green onions and water in the slow cooker.
Stir to combine.
Cover and cook on high for 3 hours or low for 4-6 hours.
Top with more green onions and some sesame seeds.
Serve over white rice.
ENJOY!