Start with the dressing. Simply mix all the dressing ingredients together in a small bowl and put to one side whilst you prepare the rest of the salad.
Cover the rice noodles in boiling water and leave to stand for 3 minutes - until the rice noodles are cooked. Drain and rinse under the cold tap to stop the noodles sticking together. Leave to drain in a colander.
Heat a small frying pan until very hot. Spray the steak on both sides with the spray oil and rub in the salt and pepper. Place the steak in the pan and cook for 2-3 minutes on each side so that it's charred on the outside, but still pink in the middle (cook for a couple of minutes longer if you prefer your steak well-done). Take the steak out of the pan and place on a chopping board. Cover with foil and then a tea-towel on top and leave to rest for 5 minutes.
Whilst the steak is resting, divide the salad leaves, cucumber, carrot and spring onions between two bowls. Top with the noodles.
Take the foil off the steak and slice into thin slices (against the grain). Divide the slices between the two bowls and sprinkle on the sliced chillies. Serve with the dressing and slices of lime.