In a dutch oven or pot, brown beef; drain and set aside. In the same dutch oven, saute the onion, carrots, celery, basil and parsley in 1 tablespoon butter until vegetables are tender, about 10 minutes. Add the broth, potatoes and beef; bring to a boil. Reduce heat; cover and simmer for 10-12 minutes or until potatoes are tender.

Meanwhile, in a small skillet, melt remaining butter. Add flour; cook and stir for 3-5 minutes or until bubbly. Add to soup; bring to a boil. Cook and stir for 2 minutes. Reduce heat to low. Stir in the cheese, milk, salt and pepper; cook and stir until cheese melts.

Remove from the heat; blend in sour cream.