Thinly slice the beef. Mix marinade ingredients, then add the beef and marinate for 30 minutes or so while you prep the vegetables and sauce.
Cut green onions diagonally in one-inch pieces. Slice garlic cloves very thinly. Peel and finely chop ginger. Blanch broccoli florets or steam briefly in the microwave until barely cooked through and still crunchy. Mix sauce ingredients and set aside.
TIME TO COOK
Heat a wok or large skillet with 1 tablespoon of oil, and stir-fry the marinated beef just to sear it, not to cook it through. When seared, remove the beef and set aside.
In the same pan, add another tablespoon of oil, and cook the garlic and ginger until very fragrant – about 30 seconds.
Return the beef to the pan, and the reserved sauce. Bring to a brisk bubble and add the broccoli and green onions. Cook, stirring, just until the green onions soften, and serve very hot.