In a medium saucepan, combine 1 tablespoon of cornstarch with 2 tablespoons of room-temperature water, stirring until smooth. Add 1/4 cup of brown sugar, 1/4 cup of low sodium soy sauce, 2 minced garlic cloves, 1 tablespoon of grated fresh ginger, 2 tablespoons of honey, 2 tablespoons of rice vinegar, and 1 tablespoon of sesame oil. Heat over medium heat, stirring continuously until the sauce thickens, about 5-7 minutes. Once thickened, set it aside to cool completely.

Cube 1 pound of boneless skinless chicken thighs into 1-inch pieces and place them in a ziplock bag. Pour half of the cooled teriyaki sauce over the chicken, ensuring it is well coated. Seal the bag, refrigerate, and let it marinate for at least 30 minutes, enhancing the flavor (up to 3 hours for a richer taste).

About 15 minutes before grilling, soak wooden skewers in water to prevent burning. Preheat your grill to medium heat (around 350°F). While waiting, thread the marinated chicken pieces onto the skewers, leaving a little space between each piece for even cooking.

Once the grill is hot, arrange the skewers on the lightly oiled grates. Grill for 20-30 minutes, turning every 3-4 minutes to ensure even cooking. Look for the chicken to reach a golden-brown color with slight caramelization, indicating a delicious glaze from the teriyaki sauce. Make sure the internal temperature reaches 165°F.

After grilling, carefully remove the skewers from the grill. Drizzle the remaining teriyaki sauce over the top for extra flavor and garnish with optional chopped green onions and sesame seeds. Serve hot.