In a medium size sauce pan, add the broth and whisk in the ginger, garlic powder, white pepper, and cornstarch until combined. Over medium heat, bring mixture to a gentle simmer.
As you bring the broth to temperature, whisk eggs in a small bowl or cup (something with a pour spout is ideal).
Once broth has begun to simmer, create a whirlpool by stirring broth in a circular motion with a whisk. Very slowly, pour a stream of the beaten eggs into the broth while continuing to stir. Ribbons of egg will form.
Remove pan from the heat and whisk in sesame oil and additional white pepper if desired. Top with green onions and serve immediately.