

Marinade
Simmer everything in a small saucepan until the sugar has dissolved. Cool completely.
Salmon
Pour the cold marinade over the salmon and set aside 30 minutes, turning occasionally.
Noodles
Toss the cold noodles with the oil and sesame seeds and set aside.
Salad
Sprinkle the carrot and cucumber with 1/2 teaspoon of the salt, mix well and set aside 20 minutes. Wash well in plenty of cold water and squeeze tightly to remove the water. Put the carrot and cucumber into a small bowl. Mix the vinegar, sugar and remaining salt until dissolved, pour it over the carrot and cucumber and set aside 15 minutes.
Assemble
Take the salmon out of the marinade and brush it with the vegetable oil. Grill or barbecue the salmon over moderate heat on each side until it is just cooked through. Baste the salmon as it cooks with the marinade. Any leftover marinade can be strained and kept in an airtight container in the refrigerator. 
To serve: on each of 4 dinner plates put one-quarter of the noodles, one piece of hot salmon, top with one-quarter of the pickles and sprinkle with one-quarter of the spring onion. Serve immediately. Serves 4.