Cut the tomatoes into wedges and whisk the eggs in a small bowl. Set them aside.
In a medium-size pot, drizzle a tablespoon of oil and saute the tomato wedges with medium heat for 3-4 minutes or until soft. Sprinkle salt over the tomatoes.
Once the tomatoes are softened and the juice comes out, pour the chicken stock, water, and garlic in. Bring it to simmer.
Stir the soup gently in one direction and make a whirlpool. Pour the whisked egg slowly to make the beautiful egg drop.
Season the soup with soy sauce, white pepper, and sesame oil. Then add the corn starch slurry ( a mixture of corn starch and water).
Stir in chopped spring onions when the soup is starting to get thickened and glossy.
Make a taste test and add more salt, or soy sauce to your taste if needed. Transfer to a soup bowl and garnish with spring onions or coriander.