In a bowl, whisk together chicken stock, cornstarch, soy sauce garlic, ginger powders, sesame oil, red pepper flakes if you're using then mix until smooth then set as aside. If you desire you can use fresh ginger and garlic.
Cut the tomato with salt for a few minutes and set aside. This step is optional but it adds more flavor to the tomato.
Heat oil over high heat and add the tomatoes stirring as you cook, season with black pepper you don't need to add salt again of you season the tomato earlier. Allow it to cook for a few minutes until the tomatoes break down and releases it juices..
Add the chicken stock mixture and allow it to boil. Now, you want to create long egg ribbons. When the mixture is boiling stir with a ladle or even a fork to form a circular motion like a whirlpool if you would say.
Add the whisked egg and stir check the season and readjust if necessary then take it off the heat immediately. The picture of this step is not clear because of the steam.