In a small bowl, whisk together all ingredients for orange sauce, set aside
Heat oil in a sauté pan over medium high heat. Add chicken and season with salt and pepper. Allow chicken to sit undisturbed for a few minutes, until it starts to brown. Turn and allow to brown on the other side. Stir and continue to cook until cooked through (8-10 minutes).
Add broccoli to pan and cover with a lid. Allow to steam until broccoli is bright green and tender, 3-4 minutes.
Pour in orange sauce, stir everything to completely coat in sauce. Cook for 2-3 minutes, until sauce has thickened. Taste and adjust seasoning if needed. Serve right away over rice or cauliflower rice. Garnish with sesame seeds and red pepper flakes if desired.