Place the broccoli spears into a heatproof bowl and cover them with boiling water. Add a good pinch of salt and leave for 10 minutes. Drain and put to one side.
Slice the steaks into finger-sized strips and season with salt and pepper. Pound the coriander seeds in a pestle and mortar, then sprinkle over the meat so they stick to it and give it a lovely, fragrant flavour.
Heat a wok or large frying pan until very hot. Pour in a splash of olive oil and add the onions, garlic and ginger. Fry for a couple of minutes until the onions have softened a little. Drop in the seasoned pieces of beef and stir-fry for a couple of minutes. Add the broccoli spears and fry for a further 2 minutes, stirring all the time.
Pour in the soy sauce and sesame oil. Toss in the pan until everything is well coated. Serve with egg noodles or steamed rice with some sliced red chilli sprinkled over the top.
Tip: If you are feeling flash, use fillet steak instead of sirloin in your stir-fry.