Make the marinade by mixing together all the ingredients. Place the salmon fillets in a small bowl and spoon over the marinade, turning the fish so that it’s nicely coated. Cover with cling film and leave to sit for 10 mins (or longer if you have time).
Meanwhile, cook the noodles following pack instructions, then drain and sit them in a bowl of cold water.
Heat a non-stick frying pan. Add the salmon fillets, skin-side down, and leave for 3 mins. When the fish is slightly crispy, flip over and cook for a further 3 mins on the other side. Just before you remove the fish from the pan, add any remaining marinade and let it sizzle for 10 secs. Place 2 of the fillets, skin-side up, with their juices on a plate and cover with foil to keep warm. Put the other 2 fillets on another plate if using for Flaked salmon salad (see 'goes well with'), cover with foil, leave to cool, then chill.
In a frying pan or wok, heat the rapeseed and sesame oils over a high heat. Add the spring onion, garlic, chilli and ginger, and stir constantly for about 1 min. Add the sugar snap peas, pak choi and pepper, and stir for another 1-2 mins, then add the cooked noodles. Toss well, then add the soy sauce, fish sauce and lime juice, and mix until well combined and the pan is sizzling.
Remove from the heat and divide between 2 bowls. Top each with a salmon fillet and drizzle over any juices. Sprinkle with coriander and serve.