In a large pot, melt 1 tablespoon butter over medium heat. Cook and stir vegetables and beef , until beef is browned
Stir in basil and parsley. Add broth and potatoes. Bring to a boil, then simmer until potatoes are tender, usually about 10-12 minutes.
Add in the remainder of butter and stir in flour. Add the milk, and continue stirring until smooth. Make sure to 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.