To Prep
Combine the salmon, soy sauce and mirin in a shallow bowl, toss until they are well coated. Marinate for 2 hrs or if preferable, overnight in the fridge.
To Cook
Cook the noodles according to the instructions on the packet, drain and refresh briefly under cold water, ensuring that the noodles are still warm.
Combine the dressing ingredients in a large bowl and toss the noodles through. Add the chilli, spring onions, spinach and coriander and toss well. Divide between 2 plates.
Heat the oil in a frying pan. Remove the salmon from the marinade, season with salt and pepper and seat, skin-side down for 2 mins. Turn over and fry on the other side for 2 mins or until the skin is crisp.
Place the salmon (skin side up) on the noodles, top with the sesame seeds and serve with half a lime.