Season the steak with salt and pepper on both sides. Heat a good-quality heavy-based pan on the stove and add the olive oil. Test that it’s hot enough by dipping the corner of the steak into the oil – it should sizzle immediately. Cook the steak for 3–4 minutes on each side for medium-rare (for steak that is about 1.5cm thick). Remove and set aside to rest.
While the steak cooks, mix the dressing ingredients together and set aside.
While the steak rests, chop the salad ingredients using a food processor (or do it by hand).
Divide the salad ingredients between four bowls, top with thin slivers of steak, sprouts, roasted peanuts, fresh herbs and spring onions and then add a generous drizzle of dressing.