Heat oil in a non-stick wok, add finely chopped onions, white part of spring onion, green chilies in along with ginger and garlic and sauté for few minutes.
Add carrot and cabbage to the wok stir fry on a medium to high flame for few minutes.
Once veggies are stir fried then add soy sauce, stir again.
Now add veg stock, Season with salt (check as much required and not to make it too salty) allow the soup to simmer on medium flame.
Add water to adjust consistency.
Add the corn starch paste to water and stir well and let the soup thicken.
At the same time while soup is thickening add the rolled oats and let it cook for 5 min.
Lastly add green part of spring onion and vinegar, switch of the flame. Stir and check the taste.
Serve manchow soup hot topped with some baked millet noodles and garnished it with coriander leaves.