In a saucepan, heat chicken broth over medium heat. In a small bowl, mix cornstarch with 2 tbsp cold water until smooth. Stir into the broth and simmer for 2–3 minutes until slightly thickened.
Add soy sauce, white pepper, ginger, and garlic (if using). Adjust salt if needed.
Whisk eggs in a bowl. Slowly drizzle the eggs into the simmering broth while stirring gently in one direction with a fork or chopsticks. The eggs will cook instantly into ribbons.
Turn off heat. Stir in sesame oil (if using) and garnish with green onions. Serve hot!
