Preheat the Oven: Set your oven to 375°F (190°C) to preheat.
Prepare the Chicken: In a large bowl, toss the diced chicken with half a cup of teriyaki sauce, garlic powder, salt, and pepper. Let it marinate for about 5 minutes.
Cook the Chicken: Heat the vegetable oil in a large skillet over medium-high heat. Add the marinated chicken and cook for about 5-7 minutes, or until it’s mostly cooked through.
Prepare the Rice: While the chicken is cooking, prepare the instant rice according to package instructions. Usually, this involves boiling water, adding rice, and letting it sit covered for 5 minutes.
Combine Ingredients: In a large casserole dish, combine the cooked chicken, prepared rice, frozen vegetables, and the remaining teriyaki sauce. Stir everything together until well mixed.
Bake: Cover the casserole dish with foil and bake in the preheated oven for 20-25 minutes, or until the vegetables are heated through and the flavors have melded together.
Garnish and Serve: Remove from the oven, and optionally sprinkle with sesame seeds and sliced green onions before serving.
