Make the dressing by putting the pickled ginger, the wasabi, the soy, sesame oil, sugar and vinegar together in a bowl and whisk to combine. Set aside.
Cook the noodles in a large saucepan of boiling water for 3-4 minutes or until just cooked. Drain and refresh under cold water. Divide the noodles between the plates and top with the radish, salmon and the dressing. Sprinkle with the baby shiso and the black sesame seeds.