Set the instant pot to a saute mode and add oil.
Once hot, add in all chopped veggies, sauté for a minute.
Season with salt, pepper, Italian seasoning and mix well.
Add in the tomato puree followed by water or broth.
Add the vegan soup base and mix well.
Now select the Instant pot soup mode and set for 15-minutes. Close the lid and seal the vent.
After the beep, wait for the natural pressure release and open the lid.
As veggies softened, mash chunks well with help of a ladle or use a hand blender to puree the soup.
Add cashew or heavy cream and adjust salt and pepper.
Bring the soup to a boil and season with fresh basil leaves and some dried basil leaves.
Serve with Parmesan cheese, croutons and truffle oil.