Prep: 1. Chop onion, scallions, and garlic. Slice mushrooms. 3. Mince/grate ginger. Make: 1. Heat oil in a medium pot over medium-high heat. 2. Saute onions and white part of scallions until softened, about 5 minutes. 3. Add mushrooms and cook 5 minutes more. 4. Add ginger, garlic, and sriracha. 5. Add the soy sauce and vinegar and deglaze the pan. 6. Add the broth and bring to a boil, then reduce heat until the soup is simmering and let cook, stirring occasionally for about 10 minutes. 7. Combine cornstarch and water. After letting soup simmer, whisk corn starch mixture into soup and simmer until thickened, about 10 minutes. 8. Beat the egg. 9. Once soup thickens, remove from heat and slowly pour in egg, using a fork to gently whisk it into soft strands in the soup. 10. Add salt if needed and garnish with the green pieces from the scallions.
This is also great with chopped tofu, pork, or an egg on top! This soup isn't spicy, however if you prefer milder flavors reduce the vinegar and sriracha by up to half.