Pour the chicken broth into a large saucepan, then add the ginger, garlic, soy sauce, and pepper.
Bring the broth to a gentle simmer over medium heat and cook for about 5 minutes to develop the flavor.
Mix the cornstarch with the cold water until smooth, then stir the mixture into the simmering broth.
Slowly pour the beaten eggs into the pot in a thin stream while gently stirring the broth in one direction.
Allow the eggs to cook for about 1 minute, then add the spinach and most of the sliced green onions.
Simmer for another 1 to 2 minutes until the spinach has wilted and the egg ribbons are fully set.
Stir in the sesame oil, taste the broth, and serve with the remaining green onions.
