In a small bowl, combine cornstarch with water to create a smooth mixture. In a saucepan, whisk together the remaining sauce ingredients. Cook over medium heat until the sauce thickens, about 5-7 minutes. Remove from heat and cool.

Cut the chicken thighs into uniform cubes. Place in a zip-lock bag and pour half the cooled teriyaki sauce over the chicken. Seal and refrigerate for at least 30 minutes.

Soak the skewers in water for 15-30 minutes. Preheat the grill to medium heat. Thread the marinated chicken onto the skewers.

Place the skewers on the grill, cooking for 20-30 minutes, turning every 3-4 minutes, until the chicken reaches an internal temperature of 165°F.

In the final minutes of grilling, baste the chicken skewers with the remaining sauce to enhance flavor.

Remove the skewers, let them rest, then sprinkle with green onions and sesame seeds. Serve warm with jasmine rice or salad.