stir fry on a medium to high flame for 3 to 4 minutes.
in the meantime, if you have cooked noodles, then add them to oil for frying. this is an optional step.
fry the noodles till they are crisp. drain the fried noodles on kitchen paper towels.
once the veggies are stir fried for 3 to 4 minutes, then add soy sauce and black pepper. stir.
now add water or veg stock.
season with salt. allow the soup to come to a simmer on a medium flame. keep a check on the amount of salt as soy sauce already has a lot of salt.
meanwhile. make a smooth paste of the corn starch with water.
add the corn starch paste to the soup. stir very well and let the manchow soup thicken.
lastly add rice vinegar or regular vinegar. switch off the flame. stir and check the taste. add more seasonings like salt, black pepper or soy sauce or vinegar if required.
stir and serve vegetable manchow soup hot topped with fried noodles. you can also mix chopped coriander leaves towards the end or serve the soup garnished with coriander leaves.