In a large skillet, add broccoli and vegetable stock. Cover and cook on medium to high heat for about 6-8 minutes or until stock has evaporated, and broccoli is cooked to your desired tenderness. You may choose to add a few more dashes of stock to soften the broccoli more if you want.
Remove the broccoli from the skillet, and keep warm. In the same skillet, add the cubed chicken and cook for ~6-8 minutes over medium heat, or until chicken is cooked all the way through. Be sure to flip the chicken cubes with a fork or tongs halfway through to promote even cooking.
While the chicken is cooking, whisk all of the other ingredients (aside from the sesame seeds) in a small bowl. Once the chicken is cooked, pour the sauce into the pan, and add the broccoli. Stir until the sauce begins to thicken and the broccoli and chicken are coated. Top with sesame seeds, salt and pepper to taste. Enjoy!
Cook the broccoli to your desired tenderness. If you would like to make this for meal prep or to reheat later in the week, broccoli that is slightly undercooked at first may be ideal.