Cook the Rice: Rinse the rice thoroughly.

Cook according to the package instructions.

Fluff with a fork, set aside, and keep warm. Season with salt and pepper.

Prepare the Teriyaki Sauce: In a small bowl, mix soy sauce, rice wine vinegar (or mirin), sake, and brown sugar. Set aside.

For the Chicken: Season the diced chicken with salt and black pepper.

Heat vegetable oil in a large skillet over medium-high heat.

Add the chicken and cook until browned on all sides.

Pour the teriyaki sauce over the chicken. Add the broccoli.

Reduce heat to medium and let it simmer until the sauce thickens and coats the broccoli is tender (about 5 minutes).