Fish Tofu Chowder

Name: Fish Tofu Chowder
Ingredients: 4 - 5 dried black mushrooms (soaked to soften); 1/2 lb firm white fish fillet (coarsely chopped); 1 teaspoon cornstarch; 1/4 teaspoon salt; 4 cups fish stock or chicken broth; 2 tablespoons rice vinegar; 1 tablespoon grated ginger; 1 teaspoon sesame oil; 1/8 teaspoon ground white pepper; 1/2 lb soft tofu (drained and cut into small cubes, about ½ lb); 2 tablespoons goji berries (soaked to soften); 3 tablespoons cornstarch (dissolved in 3water); 1 tablespoon chopped cilantro (optional)