Dice chicken thigh meat into small strips or cubes. Personally, I like to get rid of as much fat as possible but you can leave some if you choose.
Dice broccoli into small florets. (Smaller pieces of broccoli will cook faster.) Set aside.
Whisk all ingredients for the sauce together in a bowl first, making sure you whisk in cornstarch well. Set aside.
Preheat a large cooking pan over medium-high heat and add some oil. Add diced chicken to the pan and sear it until golden brown.
Add diced broccoli. Stir chicken and broccoli and let it sear on other sides. Lower the heat to medium.
When chicken is almost done, whisk sauce one more time and pour it in the pan. Slowly stir everything together and let it simmer until sauce is thickened and chicken is done.
Divide rice into plate and top with off with chicken, sauce, and broccoli. Sprinkle each plate with green onions. (Sesame seeds are optional.)