Sauté onion and carrots in butter until onions are tender. Stir in curry and cook for another minute.

Add remaining ingredients except herbs, and bring up to a boil.

Cover and simmer until veggies are tender, about 15 minutes. Add more stock or water if necessary, although a lot of moisture will be released from the zucchini.

Using a food processor or immersion blender, process soup until smooth. Add more water or chicken stock to thin soup out as desired.

For a creamier soup, add a dollop of sour cream to each bowl.