Simmer broth, ginger, corn, soy sauce, and white pepper in 4-quart pot for 4 minutes until corn hot.
Mix cornstarch with cold water; stir into simmering broth. Cook 1 minute until lightly thickened.
Gently add tofu; heat 2 minutes, keeping cubes intact. Reduce to very gentle simmer.
Slowly stir broth in one direction; pour eggs in thin stream. Stop stirring 30 seconds; gently lift ribbons and cook 1 to 2 minutes until fully set and 160°F.
Off heat, stir in sesame oil. Divide among 4 bowls; scatter measured scallions evenly.