Combine chicken and marinade. Mix well and refrigerate at least 24 hours.
In a small pot, bring chicken broth and ginger to a gentle boil.
Add remaining sauce ingredients and add cornstarch slurry to thicken. Adjust sugar and soy sauce to taste. Slightly overthicken to compensate for the chicken juices that will come out during cooking.
Drain chicken and allow to come to room temperature. Over high heat, grill on an oiled pan 4-5 minutes each side. Do in batches as necessary to avoid overcrowding.
Add the sauce and cook a minute or two more to incorporate and thicken.
Plate and garnish with sesame seeds if desired. Serve with steamed rice.