Soak mekabu in hot water to cover for 10 minutes, drain, and soak in cold water for another 2 minutes. Drain the mekabu and set aside. Cook udon as package directs, rinse and drain. Place udon, mekabu, carrot, cabbage and scallions in a mixing bowl. Combine remaining ingredients for the dressing, mix and pour over the udon. Gently toss to mix.
Per serving - 218 calories, 5 g fat (21% calories from fat), 7 g protein, 36 g carbohydrate, 5 g fiber, 0 mg cholesterol, 914 mg sodium