In 5 quart pot, brown beef, drain & set aside. Saute onions, carrots, celery and basil in same pan about 5 minutes. Stir in flour and add broth, potatoes and beef.
Cover, reduce heat and simmer until potatoes are tender, about 15 minutes.
Add cheese, milk, salt & pepper. Cook and stir until cheese melts.
Remove from heat and blend in sour cream.