Brown the ground beef. Season with salt and pepper. Drain and take the beef out of the pan. In the same pan add 1 tablespoon butter, onion, carrots, parsley, basil and celery. Saute until tender. Add the broth, potatoes and beef and bring to a boil. Reduce the heat, cover and simmer 10-15 minutes or until potatoes are tender. In a small skillet melt the remaining butter add the flour. Cook and stir for 3-5 minutes or until bubbly. Add to the soup and bring to a boil. Cook and stir for 2 minutes. Reduce to low. Stir in the cheese and milk, Cook and stir until cheese melts. Remove from heat and blend in sour cream.