Heat the chicken broth in a saucepan over medium-high until it simmers.
Mix cornstarch and water in a bowl until smooth to create a slurry.
In another bowl, whisk the eggs with white pepper and sesame oil.
Gradually pour the egg mixture into the simmering broth, stirring continuously in a circular motion to form egg ribbons.
Blanch green onions in boiling water for 30 seconds, then drain.
Stir the cornstarch slurry again, add to the soup, and stir until slightly thickened.
Season with salt, taste, and adjust as necessary.
Serve hot, garnished with blanched green onions.
