firstly, heat 1 tbsp oil in a pan and fry finely chopped onions for a minute or 2.
next saute chopped ginger and garlic.
furthermore, add veggies. add the finely chopped french beans, grated carrot and shredded cabbage. stir well.
also add sliced mushrooms and stir fry till the mushrooms get lightly browned from the edges.
furthermore, once the mushrooms are lightly browned add water and boil.
further, add soy sauce and stir well.
finally season with some salt.
furthermore, stir the corn starch with some water and make a paste out of it. add it to the soup accordingly.
lastly, bring the soup to a simmer on medium flame for 2 minutes.
also when the soup has thickened, add vinegar.
also add black pepper. give a final stir. switch off the flame.
finally, serve the veg hot and sour soup steaming hot garnished with spring onion.