Fill a large pan with 1ltr (1 3/4pt) freshly boiled water and stir in the miso. Add the ginger and star anise, then leave to simmer over a low heat. Meanwhile, cook the noodles following the packet instructions; drain. Heat a heavy-based frying pan over a high heat until smoking. Lightly oil the steaks with a little of the olive oil and season well. Cook, for 2-3 minutes on each side (or 1-2 minutes, for rare meat), until browned but still pink in the middle. Remove and set aside to rest. Add the mushrooms and greens to the miso broth and continue simmering for 5 minutes. Meanwhile, heat the remaining oil in a separate pan and fry the chilli, spring onions and coriander stalks, until just softened. Slice the steaks thinly. Divide the noodles between 4 bowls and ladle over the broth. Top each with the steak strips, chilli mixture and remaining coriander. Serve immediately.
