Make the slurry. Pour ¼ cup of the chicken broth into a measuring cup. Stir in the cornstarch, to create a slurry.
Make the soup. Pour the remaining 3 ¾ cups of chicken broth into a saucepan and bring to a simmer over medium heat. Add the ground ginger, soy sauce, sesame oil, salt, and white pepper, and stir to combine. If you'd like to add the turmeric, you can add that now as well. While continuously stirring, pour in the cornstarch slurry. Simmer and stir for another minute, until slightly thickened.
Create the egg ribbons. Reduce the heat to low, and stir in a circular motion. While stirring, very slowly pour the beaten eggs in a thin stream, to create the egg ribbons. Let the eggs sit for 30 seconds to fully form, before stirring again.
Garnish and serve. Ladle the soup into bowls and garnish with a sprinkle of sliced green onions before serving.
