In a bowl, add the sliced beef along with the marinade ingredients. Mix well to ensure the beef slices are coated. Set aside to marinate for at least 30 minutes.
Meanwhile, mix all the sauce ingredients in a bowl or jug and set aside.
Blanch the broccoli pieces in a pan of boiling water for 1 minute. Drain and set aside.
Heat a wok over a high heat until smoking, then add 2 tbsp of the groundnut oil. Add the marinated beef and stir-fry, for 2 minutes, until browned all over. Turn off the heat, remove the beef from the wok, and set aside.
Return the wok to a medium heat and add the remaining tbsp of groundnut oil along with the garlic. Stir for 5 seconds, then pour the Shaoxing cooking wine around the perimeter of the wok.
Add the sauce and stir it around the sides of the wok to deglaze it (all those nice bits from cooking the beef should be absorbed into the sauce). Bring the sauce to a simmer, then drizzle in the cornflour slurry, stirring constantly. Allow it to simmer and thicken for 20 seconds.
Toss in the blanched broccoli and beef (along with any resting juices). Mix everything together over a medium heat until the sauce coats the beef and broccoli. If the sauce seems thin, turn up the heat and reduce it further, or add a bit more cornflour slurry. If the sauce is too thick, add a splash of chicken stock or water. Serve with your choice of Chinese side dishes.
Notes
To achieve the best results with the sirloin steaks, you need to make sure that the meat is sliced thinly (about 0.5cm slices). One way to do this is to freeze the steak for 30 minutes before slicing it. This allows you to easily slice through the steak. Of course, you'll also need a sharp knife that can do the hard work for you.
Optional variations:
Extra spicy chilli beef – add fresh chillis or crispy chilli in oil for an extra kick of heat.
Garlic beef and broccoli – increase the amount of garlic.
Ginger and honey version – add runny honey and grated ginger to the sauce.
Teriyaki beef – replace some of the soy sauce with teriyaki sauce.
Low-carb version – serve over cauliflower rice or shredded cabbage.
Extra veg version – add veggies like mangetout, sugar snap peas, diced peppers, mushrooms, baby corn or carrots.
Chicken version – replace the sirloin steak with strips of chicken thighs or breast.
This spiced beef and broccoli recipe is easily adapted if you’re cooking for less or more people.