1.In a bowl, combine soy sauce, mirin and sugar. Add salmon, tossing to combine. Marinate 15 minutes.
2.Meanwhile, cook noodles following packet instructions. Drain well.
3.Heat half oil in a large frying pan or wok on medium. Remove salmon from marinade. Cook 2 minutes, turning on all sides, until golden and just cooked through.
4.Transfer to a large bowl with extra soy sauce, extra mirin, sesame oil, remaining olive oil, ginger and pickling liquid. Toss to combine.
5.Divide noodles among four serving bowls. Top evenly with broccolini and salmon.