4 Servings 15 min Cook
1/4 Cup Cornstarch
1/4 Cup Water
8 Oz Beef Flank
1 Tsp Salt
2 Tsp Vinegar
1 Tsp Fish Sauce
1 Tsp Sesame Oil
1 Tsp, ground Pepper
6 Cup Chicken Stock
10 Mushroom Mushrooms
3 Egg white (separated from yolk) Egg White
4 Cup Fresh Cilantro
3 Medium (4-1/8" long) Scallions
Make a slurry with the cornstarch and water; set aside.
Combine the beef, salt, vinegar, fish sauce, sesame oil, and 1/4 tsp of white pepper in a bowl.
Bring the broth and mushrooms to a boil over high heat in a saucepan.
Lower the heat to maintain a simmer, and add the cornstarch slurry to thicken the soup, stirring well to incorporate.
Once the soup thickens, add the marinated meat and stir well.
As soon as the meat is cooked through, about 30 seconds to a minute, turn off the heat.
Season the soup with salt and white pepper to taste.
In a slow, steady stream, pour in the egg whites from high above the pot, stirring as the whites hit the liquid.
The whites will cook upon contact with the hot soup, forming ribbon like tendrils.
Mix in the cilantro and scallions.
Ladle into bowls and serve immediately.