In small bowl, cover mushrooms with 1 cup (250 mL) warm water; let stand for
20 minutes or until softened. Drain, reserving liquid. Discard stems and finely slice caps; set aside.
In large bowl of warm water, soak noodles for 5 minutes; drain, and place in pile on cutting board. Cut pile in half; set aside.
Cut tofu into thin slices.
Cut pork into thin strips; toss with 1 teaspoon (5 mL) of the cornstarch.
In large pot, bring chicken stock to simmer. Add pork, reserved mushrooms, soaking liquid, noodles and tofu, vinegar, soy sauce, sugar, pepper; simmer for 3 minutes.
In small bowl, whisk remaining cornstarch with 1 tablespoon (15 ml) cold water; add to soup and simmer for 2 minutes. Remove from heat. In small bowl, whisk eggs with
1 tablespoon (15 mL) water, drizzle into soup, stirring slowly with spoon to form streamers. Stir in coriander leaves, sesame oil and onions.