Measure the sauce ingredients directly into a small bowl or lidded jar. If using a jar, put the lid on and shake well to combine; otherwise, use a whisk to combine the ingredients well.
Cook the chicken:
On a flat surface, pat dry the chicken breasts and cube them.
Heat a large pan over medium-high heat, add the oil, and heat it up for about 30 seconds. Place the cubed chicken breast pieces in the pan in an even layer and let them cook, undisturbed, for about 4 minutes. Flip them around and cook them for another 3 to 4 minutes until the internal temperature is 165F.
While the chicken cooks, prepare the dry rice according to the package directions.
To the cooked chicken, add the sauce, stir to coat, and reduce the heat to medium-low to simmer for 5 minutes.
Cook the broccoli:
If using fresh broccoli florets, steam them in a steamer, microwave, or cook them in a pan over medium-high heat, with ½ cup of water with the lid on, for approximately 5 minutes, until the broccoli has the crisp texture and doneness you like. If using a frozen bag of broccoli florets, steam them directly in the microwave.
Combine:
Assemble the chicken broccoli teriyaki bowls by layering the rice, chicken, and broccoli, and drizzle them with sauce. Sprinkle sesame seeds on top, if using.
Notes
Dry ginger: use ⅛ teaspoon of powdered dry ginger.
Frozen broccoli: use a 16-ounce bag of frozen broccoli. You can steam it in the bag in the microwave or in a pot or pan.