In a large saucepan over medium heat, cook and crumble beef until no longer pink, 6-8 minutes; drain and remove from pan.
In same saucepan, melt 1 tablespoon butter over medium heat. Saute onion, carrots, celery, basil and parsley until vegetables are tender, about 10 minutes.
Add potatoes, broth and beef; bring to a boil. Reduce heat; simmer, covered, 10-12 minutes or until potatoes are tender.
Meanwhile, in a small skillet, melt remaining 3 tablespoons butter. Add flour; cook and stir until bubbly, 3-5 minutes.
Add to soup; bring to a boil. Cook and stir for 2 minutes.
Reduce heat to low. Stir in cheese, milk, salt and pepper; cook until cheese melts.
Remove from heat; blend in sour cream. If desired, serve with onion rings and green onion.
