Bring the chicken stock to a simmer in a medium soup pot.
Stir in sesame oil, salt, sugar, white pepper, turmeric or food coloring, and MSG if using.
Mix cornstarch with water and stir to dissolve.
Slowly drizzle cornstarch mixture into the simmering soup while stirring to thicken.
Stir soup in one direction to create a swirl.
Slowly pour in lightly beaten eggs while stirring to create egg ribbons.
Turn off heat. Top with chopped scallions and serve hot.
