In a saucepan, brown beef; drain and set aside.
In the same pan, saute the onion, carrots, celery, basil and parsley in 1 tbls of butter for about 10 minutes or until vegetables are tender.
Add 3 C broth, potatoes and beef and bring to a boil. Reduce heat, cover and simmer for 10-12 mins until potatoes are tender.
While simmering, in a small skillet, melt remaining butter and add flour. You may need to add extra broth to make a smooth rue. Cook and stir for 3-5 minutes.
Add to soup and bring to a boil. Cook and stir for 2 mins.
Reduce heat to low.
Stir in cheese, milk, salt and pepper and stir until cheese melts.
Remove from heat and blend in sour cream.