For the beef, place the fillet in between two sheets of cling film and bash with a meat mallet or rolling pin until half as thin.
350 g beef fillet
Slice the beef into thin pieces and place into a bowl, then season with the light soy sauce, oyster sauce, sugar and salt and freshly ground black pepper. Put to one aside.
Stir-fry for a few seconds, then add the spinach leaves and toss for a few seconds, until warmed through. Pile onto a large serving plate.
200 g baby spinach
Place the wok back on the heat and add the remaining oil, then add the beef slices and stir fry for 2-3 minutes, or until the beef is cooked to your liking.
Pour in the Shaoxing rice wine and sprinkle over the dried chilli flakes.