Wash and chop all the veggies finely.
Heat butter in a pot, add veggies except spring onions. Saute 2 minutes.
Add water and boil till all the veggies get cooked. Cooking on a low flame makes the soup taste better.
While the soup boils, mix corn starch in little water. This is optional. When the veggies are soft cooked, pour this to the pot and stir till it thickens.
Add salt and sugar as well.
Serve warm with pepper.