Rinse the veggies thoroughly and chop them finely. You can also use a food processor.
Chop or mince ginger and garlic.
Heat oil in a pot.
Fry garlic, ginger, bay leaf (optional) and spring onion whites for a minute.
Then add all the other veggies and saute for 2 mins on a high flame to bring out the aroma.
Pour water or stock and cook covered until the veggies are slightly tender.
Meanwhile stir in the corn starch in ¼ cup water.
Pour the corn starch mixture to the boiling vegetable soup.
Cook stirring constantly until it turns slightly thick. It will thicken further upon cooling.
Add pepper, salt & sugar. Stir and turn off the stove. Let it cool down a bit.
Then add in vinegar and chilli flakes. Taste and add more salt if needed.
Serve vegetable soup hot or warm with some hakka noodles or cheese toast.