In separate bowls, soak the dried daikon and hiziki in warm water to cover for 15 minutes each. Chop the dried daikon and reserve the soaking water. Discard hiziki soaking water. Heat up the oil, and sauté the onions for 2 to 3 minutes. Add the dried daikon, carrots, hiziki, and water. Cover, bring to a boil, and reduce the flame to medium-low. Simmer for 30 minutes, or until hiziki is tender. Add shoyu, cover, and simmer 5 minutes. Remove cover, add leeks or snow peas, mix and cook off all remaining liquid. Serve.
Per serving - 65 calories, 2 g fat (25% calories from fat), 2 g protein, 10 g carbohydrate, 3 g fiber, 0 mg cholesterol, 244 mg sodium