Brown beef, drain and set aside. Sauté onions, carrots, celery, basil and parsley in 1 T. butter until vegetables are tender, about 10 minutes. Add broth, potatoes and beef; bring to a boil. Reduce heat; cover and simmer for 10 minutes or until potatoes are done.
Meanwhile, in a small skillet, melt remaining butter. Add flour, cook and stir 3-5 minutes or until bubbly. Add to soup, bring to boil. Cook and stir for 2 minutes. Reduce heat to low. Add cheese, milk, salt and pepper. Cook and stir until cheese melts. Remove from heat, add sour cream.