In a large pot over medium heat, add 2 tbsp cooking oil along with ginger, garlic, and green chilies. Sauté for 30-60 seconds until fragrant.
Add the diced Shiitake mushrooms, and sauté to sweat out the moisture and tender, 2-3 minutes.
Add the shallots and sauté until slightly softened, 30-45 seconds.
Add the carrots, green beans, green bell pepper, and whites of the scallions, and sauté for 30 seconds.
Add the green cabbage, ground black pepper, red chili sauce, light soy sauce, and dark soy sauce and stir to combine for 30 seconds.
Add the vegetable broth and bring to a boil.
Slowly pour in the cornstarch slurry while stirring continuously.
Simmer for 2-3 minutes until the soup thickens.
Garnish with chopped cilantro and sliced scallions before serving.