TERIYAKI SAUCE: In a small saucepan over medium heat, combine 1/4 cup cold water and cornstarch. Stir in soy sauce, mirin, brown sugar, honey, ginger, garlic and sesame oil. Bring to a boil; reduce heat and simmer, stirring occasionally, until thickened, about 4-5 minutes. Let cool completely.
In a gallon size Ziploc bag or large bowl, combine chicken and 1/2 cup TERIYAKI SAUCE; marinate for at least 2 hours to overnight, turning the bag occasionally. Drain the chicken from the marinade.
Preheat grill to medium high heat. Brush chicken with canola oil.
Add chicken to grill, and cook, turning occasionally, until chicken is completely cooked through, reaching an internal temperature of 165 degrees F, about 10 minutes. Brush chicken with TERIYAKI SAUCE, cooking for an additional 1-2 minutes.
Serve immediately with remaining TERIYAKI SAUCE, garnished with green onions and sesame seeds, if desired.