In a large pot add ground beef, onion, carrots and celery, sprinkle with salt and pepper and cook over medium high heat until beef is browned.
Stir in basil and parsley. Add broth and potatoes. Bring to a boil, then simmer until potatoes are tender, about 10-12 minutes.
Melt the butter and stir in flour. Add the milk, stirring until smooth.
Gradually add milk mixture to the soup, stirring constantly. Bring to a boil and reduce heat to simmer. Stir in cheese. When cheese is melted, add sour cream and heat through. Do not boil.