Instructions:
- Marinate the beef: Whisk together marinade ingredients (soy sauce, sherry, water, grated ginger, garlic & corn starch) in a medium bowl. Add beef and toss to coat. Set aside.
- Make the sauce: Whisk together sauce ingredients (beef broth, corn starch, soy sauce, sesame oil, honey, grated ginger and garlic) in a small bowl until smooth. Set aside.
- Stir fry the vegetables: Melt 2 tablespoons butter in a cast iron skillet or wok over medium-high heat. Add broccoli and green onions. Season with salt and pepper and stir fry for 3-4 minutes or until bright green and lightly charred. Remove from the pan and set aside.
- Sear the beef: Melt remaining butter in the skillet and add steak to pan, searing on each side for 2 minutes or until done.
- Add the sauce: Pour the sauce into the skillet and cook until thickened, about 2 minutes.
- Combine and serve: Return the vegetables to the pan and toss everything together until evenly coated and heated through. Serve immediately over 4 cups of cooked rice.
Notes: Slice the flank steak as thin as possible (about ¼ inch) for the most tender results. Partially freezing the steak for 20–30 minutes before slicing makes this much easier. The sauce can be made ahead and refrigerated for up to 3 days.