In a small pot, whisk together all the ingredients for the sauce together (except for the green part of the scallions and the corn starch). Cook over medium high heat and let it reduce. If it is not thick enough by the time the chicken is done, add a little corn starch.
Coat chicken in corn starch (I usually throw it in a bag and shake it around).
Remove excess corn starch and shallow fry the chicken in vegetable or canola oil until brown all around. Add broccoli and sauté another minute or so.
Add orange sauce directly to pan and cook for a few minutes until everything is coated nicely. You may not need all the sauce you make, so pour it in a little at a time.
Finish the dish off by plating it and topping it with the green parts of the scallions.