**Preheat the Oven:** Preheat your oven to 375°F (190°C).
**Make the Teriyaki Sauce:** In a mixing bowl, whisk together soy sauce, brown sugar, honey, rice vinegar, sesame oil, garlic, and ginger. Transfer the mixture to a saucepan and heat over medium heat. Stir in the cornstarch slurry and cook until the sauce thickens, about 2-3 minutes.
**Prepare the Chicken:** Place the chicken breasts in a baking dish. Pour the teriyaki sauce over the chicken, ensuring it is evenly coated.
**Bake:** Cover the baking dish with aluminum foil and bake for 25 minutes. Remove the foil, baste the chicken with the sauce, and bake for an additional 10-15 minutes, or until the chicken reaches an internal temperature of 165°F (74°C).
**Garnish and Serve:** Remove the chicken from the oven and let it rest for 5 minutes. Sprinkle with sesame seeds and chopped green onions before serving.