Prepare the Teriyaki Sauce: In a small bowl, mix 1 tablespoon cornstarch with 2 tablespoons water and set aside. In a medium saucepan, combine 1/4 cup brown sugar, 1/4 cup soy sauce, 2 minced garlic cloves, 2 tablespoons rice vinegar, 1 tablespoon minced ginger, and 1 tablespoon honey. Heat this mixture over medium heat, stirring frequently until thickened.

Marinate Chicken: Cut chicken into bite-sized cubes and place in a zip-top bag. Pour half of the cooled teriyaki sauce over the chicken, seal tightly, and marinate in the refrigerator for at least 30 minutes or up to 24 hours.

Prepare Your Grill: Preheat the grill to medium heat. If using wooden skewers, soak them for at least 30 minutes. Thread marinated chicken onto skewers.

Grill the Skewers: Place skewers on the grill and cook for 20-30 minutes, turning every 3-4 minutes until chicken reaches 165°F. Baste with remaining teriyaki sauce during the last few minutes.

Serve and Garnish: Remove from grill, let rest briefly, then top with chopped green onions and sesame seeds. Serve with rice and vegetables.