Heat the olive oil in a large soup pot on medium heat. Add the onion and cook for approximately 2 minutes, stirring frequently, until onions are translucent.
Stir in the fresh ginger, curry powder and cardamom. Add the chopped garlic and sauté for one minute.
Add the parsnips, apples, vegetable stock and apple cider. Bring to a boil, then reduce to a simmer. Simmer for approximately 30 minutes or until the parsnips are fork tender.
Place half of the mixture in a blender or food processor. Puree until smooth. Place in a new pot. Puree the remaining soup.
Reheat soup and season with the salt and white pepper. Ladle into bowls and garnish with a dollop of sour cream or Greek yogurt and a grind of fresh black pepper.
Serves 6 to 8