Wash and clean your hands and preparation area. Rinse any fresh vegetables under cool running water before chopping.
Cut the chicken breast into bite-size pieces. Heat the olive oil in a large pan over medium to medium-high heat. Cook the chicken breast in the pan for about 5-7 minutes or until pink can no longer be seen.
While chicken is cooking, combine water, corn starch, sesame oil, sriracha sauce, soy sauce, garlic, and ginger in a bowl and whisk together until well combined.
Reduce the heat to medium and add the broccoli florets to the pan and combine the chicken and broccoli. Add in the sauce mixture then cover and cook for about 5-10 minutes, stirring occasionally.
Remove the lid and continue to cook until sauce has thickened and chicken has reached a minimum internal temperature of 165°F. Top with sesame seeds and serve over brown rice.