Cook rice according to the instructions given. Once it finishes cooking, set aside. If desired, mix in lime juice and chopped cilantro after cooking.
While the rice cooks, set a nonstick skillet on medium heat and lightly spray with cooking spray.
Add the chicken chunks and cook until the outside is golden brown and no longer pink, about 6 to 8 minutes. Set the chicken aside.
Using the same skillet, increase the heat to medium high, spray with a little cooking spray, then add the chopped vegetables. Cook and sear the vegetables until the outside edges are brown, about 4 to 6 minutes.
Add the chicken back to the skillet and mix everything together. Reduce the heat, then pour in the teriyaki sauce. Shake the skillet to mix.
Serve the stir-fry over brown rice and garnish with freshly chopped green onion.