Place the meat in a ziplock bag. Stir the cornstarch and cold water in a small bowl. Add this to the bag with the meat. Marinade for at least 20-30 minutes.
Heat the vegetable oil in a large skillet over medium high heat. Add the chopped broccoli onto the skillet. Sauté covered for 3-4 minutes until slightly tender. Then stir in the marinated beef. Sauté uncovered for an additional 3-4 minutes until the beef is cooked through and the broccoli is tender.
Combine all the sauce ingredients together in a small bowl. Pour the sauce over the beef and vegetables and toss to combine. Heat for 1 minute to make sure that all the flavors are combined and heated through.
Remove from heat, serve warm over cooked rice and enjoy!
Notes
We used flank steak for this recipe, but you can easily use skirt steak or sirloin steak as well. Refrigerate the leftovers in an airtight container for up to 5 days.