Combine sesame oil, soy sauce, light brown sugar, orange juice, hoisin sauce, ground or rehydrated ginger and garlic in a bowl. Mix well and set to the side.
Place the chicken in a slow cooker then pour the sauce mixture over the chicken. Cover and cook on LOW for 2 1/2 hours or until chicken is tender. Transfer chicken to a platter; keep warm.
Pour cooking liquid through a sieve into a small saucepan to measure 1 1/4 cups. Discard the strained solids.
Bring the sauce to a boil over medium-high heat. Combine the cornstarch and cold water in a small bowl and mix until incorporated.
Add cornstarch mixture to sauce, stirring with a whisk until blended. Cook for 1 minute or until sauce thickens, stirring constantly.
Pour sauce over the chicken and sprinkle with sesame seeds and green onions.
Keyword Asian, Chicken, Easy, Easy Dinners, Ginger, One Pot Meals, Sauces, Slow Cooked, Slow Cooker