In a large pan, saute the onions and carrots and ginger together in butter till they are soft. Once the color of the onions turns a bit golden add 2 cups of chicken stock and simmer until the carrots are completely cooked through.
Once the vegetables are cooked, pour the mixture in the Vitamix and blend till the soup is smooth and without any lumps for about 30 - 45 seconds.
Add in the remaining cups of chicken stock and blend till smooth. Once you are happy with the consistency to turn the mixture off and serve the soup hot with your favorite garnish.