Easy Fish Tofu Soup

For the fish & marinade:

• 8 oz. tilapia or catfish fillet (225g, sliced thinly on the diagonal)
• ½ teaspoon cornstarch
• 1 teaspoon light soy sauce
• 1 teaspoon Shaoxing wine
• ¼ teaspoon sesame oil
• ¼ teaspoon salt
• 1/8 teaspoon white pepper

For the soup:

• 2 tablespoons oil
• 1-2 thinly sliced ginger
• 6 fresh shiitake mushrooms (sliced; reconstituted dried shiitakes are also fine)
• 6 dried red chilies (optional, but they certainly add some nice heat)
• 1 cup soybean sprouts (mung bean sprouts will also work)
• 4 cups chicken stock (950 ml)
• 1 1/2 cups water (355 ml)
• 1 cup Napa cabbage (cut into 1-inch pieces)
• ½ pound firm tofu (225g, sliced into 1/2-inch thick slices)
• ½ teaspoon sesame oil
• salt (to taste)
• chopped scallion
• chopped cilantro