Heat sesame oil in a large pot over medium heat. Add mushrooms and cook until mushrooms start to soften, about 3 minutes. Add ginger and garlic and cook for 1 minute more.
Add stock and soy sauce to pot and increase heat to bring to a boil.
Add noodles and cook according to package instructions until al dente, which should be just a few minutes. Be careful not to overcook noodles.
Stir in cooked chicken and scallions. Taste and add salt if desired.
Serve immediately, adding toasted sesame seeds on top.
Calories: 244kcal, Carbohydrates: 17g, Protein: 20g, Fat: 10g, Saturated Fat: 2g, Cholesterol: 37mg, Sodium: 1365mg, Potassium: 650mg, Fiber: 1g, Sugar: 7g, Vitamin A: 104IU, Vitamin C: 3mg, Calcium: 34mg, Iron: 2mg