Preheat the oven to 425F. Spray a 9x13 inch casserole pan with nonstick spray.
In a medium bowl, whisk together the chicken broth, teriyaki sauce, water, sesame oil, ginger, and garlic. Add the chicken and stir to coat.
Spread the rice evenly in the bottom of the pan. Pour the chicken mixture over the rice, making sure the chicken is evenly distributed. Top with onion, broccoli, and peppers evenly.
Cover with foil and bake for 25 minutes. Remove the foil and bake until the sauce has thickened, the rice is tender, and the chicken is cooked through, about 20-25 minutes.
Let it sit for another 5 minutes before serving to allow for the rice to absorb any additional moisture.
Mix and serve topped with sliced green onions.