Spread the miso paste over both sides of the steak and leave to one side for 30 minutes.
Meanwhile heat a griddle pan or frying pan to a high heat.
Cook the steak in the hot pan for the desired length of time. For Medium cook for 3 to 4 minutes on one side without touching. Then reduce to a medium heat and cook for another 2 to 3 minutes. Gently turn again and cook for a further 5 minutes.
Remove the steak and place on a warm plate and cover.
Keep the pan on the heat and deglaze the pan with the sake or mirin. Reduce for 2 minutes to cook out the alcohol of the sake. Then pour the reduction over the steak.
Serve with lemon and ginger stir fried noodles, teriyaki noodles or chips.