Cheeseburger Soup

1 pound ground beef
1-1/2 cup chopped onion
1-1/2 cup carrots, shredded
1-1/2 cup celery, diced
1 teaspoon basil
2 teaspoons parsley
8 tablespoons butter, divided
6 cups chicken broth
8 cups potatoes, peeled and diced
1/2 cup flour
3 cups cheddar cheese, shredded
3 cups milk
1-1/2 teaspoon salt
1/2 teaspoon pepper
1/2 cup sour cream

Brown beef and set aside. In same dutch oven, saute onion, carrots, celery, basil and parsley in 2 tablespoons butter until vegetables are tender. (About 10 minutes.)
Add broth, potatoes and beef. Bring to a boil. Reduce heat; simmer (covered) for 10-12 minutes or until potatoes are tender.

Meanwhile, in small skillet, melt remaining butter. Add flour; cook and stir 3 minutes or until thick and bubbly. Add to soup; bring to a 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. Blend in sour cream.