Cook bacon slowly over medium-low heat until crisp. Set the bacon aside. Add onion and celery to fat in pan and saute until tender. Add flour and chicken stock; mix well until all flour is dissolved. Continue to stir and bring to a boil. Reduce heat to a simmer. Add potatoes and let soup simmer until potatoes are tender.
Add heavy cream, sour cream, basil and white pepper; simmer for about 10 minutes until soup is hot again.
Combine chopped parsley, crumbled bacon, chives and cheese. Garnish each portion of soup with the parsley/bacon/chives/cheese mixture.