Soak shiitake in hot water to cover for 20 minutes, remove and reserve water. Remove the stems and discard. Thinly slice the caps. Cook udon as package directs, rinse, drain and set aside. Heat up oil in a skillet and fry the tofu until golden brown, flip over and fry the other side until golden brown. Remove and drain on paper towels. Slice the tofu into thin strips and set aside.
To prepare the broth, place the shiitake, kombu, onions, fried tofu, shiitake soaking water and water in a pot. Cover and bring to a boil. Reduce flame and simmer for 10 minutes. Remove the kombu and use in another dish or discard. Reduce flame to low. Add the diluted kuzu to the broth, stirring constantly until the broth is thick. Add the shoyu and simmer 3 to 5 minutes. Place the udon in serving bowls and ladle the thick broth over each serving. Garnish each serving with equal portions of ginger, scallion and bonito flakes, if desired. Very warming on a cold winters day!
Per serving - 352 calories, 15 gram fat (37% calories from fat), 14 gram protein, 42 gram carbohydrate, 7 gram fiber, 0 milligram cholesterol, 410 milligram sodium