Bring a large saucepan of salted water to the boil, add the rice, stir well, then cook according to the packet instructions.
Heat a wok over a high heat until hot. Add half the oil and, when it’s just smoking, add the beef. Sprinkle with cornflour and stir-fry until browned all over. Remove from the pan and set aside.
Stir-fry the cashews until just golden, then set aside.
Carefully wipe the wok until clean using kitchen paper. Bring to a high heat and add the remaining oil. Once hot, add the red onion and fry for 1–2 minutes, or until just soft. Add the garlic and ginger and fry for a minute.
Add the broccoli, soy and oyster sauce to the wok and mix well. Add the vegetable stock cube with 250ml/9fl oz boiling water and bring to the boil, stirring well. Cover with a lid (use kitchen foil if you don't have a suitable pan lid) and cook for 2 minutes, or until the broccoli is just tender (you don’t want to lose the bright green colour).
Stir the cooked beef and cashews through the sauce and heat for a minute. Scatter over the chilli and coriander and serve immediately with the drained rice.
