Marinate the finely cut chicken in the rice vinegar, salt, white pepper, and chili sesame oil for 30 minutes.
How to season the broth:
In a Dutch oven, heat the peanut oil, and sauté the chili garlic paste for a few seconds. Add the chicken and sauté for 5 minutes on medium heat.
Add 10 cups of water and simmer for 10 minutes.
Julienne cut the shiitake mushrooms, bamboo shoots, and chestnuts.
Mix in the bamboo shoots, shiitake, water chestnuts, tofu, and simmer for 10 minutes with salt and sugar.
Pour in the vinegars and sauces.
How to make the cornstarch slurry:
In a bowl, mix the cornstarch and water (at room temperature) together. Just before adding to the broth, ensure that the mixture is stirred again because the cornstarch will sink to the bottom after some time.
Drizzle gently over the simmering stock. Stir well and cook on medium heat for 10 minutes.
Slowly pour the beaten egg into the broth while simultaneously stirring the broth in a clockwise direction to get the delicately laced egg ribbons. Garnish with scallions and crack some white pepper on top.
Notes
Notes:
Mix the slurry just before adding to the broth or the cornstarch will settle to the bottom.
Beat the egg well and keep stirring the soup while pouring the egg into the broth.
Marinate the chicken and sauté for added flavor.
Adjust the vinegar if you like it a little sour by adding some more to the broth.
Increase the chili-garlic paste for extra heat. I used the homemade chili garlic paste using fresh red chilis and garlic. You could use Sriracha if you like.