In a large saucepan on medium heat, cook and crumble the beef until it is no longer pink. Drain and set aside.
In the same saucepan, melt over medium heat 1 tbsp of butter.
Saute the celery, onions, carrots, basil, and the parsley until the vegetables are tender for about 10 minutes.
Add the potatoes, broth and ground beef. Bring to a boil. Reduce the heat and simmer covered with the lid, until the potatoes are tender for about 10 minutes.
In a small skillet melt the remaining butter. Add the flour, and cook and stir until bubbling for about 4 to 5 minutes. Add to the soup and bring to a boil. Cook and stir for about 2 minutes.
Reduce the heat to low, stir in the cheese, salt, pepper and milk. Cook until t he cheese melts.
Remove from the heat, and blend in the sour cream. Serve.