Place 1/2 cup cornstarch in a large plastic baggie. Add chicken cubes and toss to coat.
In a large skillet, pour enough canola oil to cover the bottom. When heated up, add chicken and cook until medium brown - be sure to not let the chicken stick to the pan.
While your chicken is cooking, make sauce: Mix water, sugar, soy sauce, oyster sauce, garlic powder and cornstarch in a small saucepan. Stir over medium-high heat until thickened. Pour over browned chicken. Stir to combine and simmer about 3 minutes.
Add broccoli florets to chicken and cover with lid. Let steam until tender to your liking.
Serve chicken and broccoli on a bed of rice and sprinkle with sesame seeds. ENJOY!!