Melt 1 tablespoon of butter in a large pot or dutch oven. Add onion, carrots, celery, and ground beef. Cook until beef is browned and vegetables are soft, stirring often, about 8 minutes.

Add garlic and cook for 1 minute, stirring often.

Add parsley, basil, potatoes and beef broth. Bring to a boil. Reduce heat and simmer for 12 minutes or until potatoes are fork-tender.

Meanwhile, in a separate small saucepan, melt the remaining 3 tablespoons of butter over medium heat. Stir in flour and whisk until smooth for 1 minute. Slowly stir in milk, whisking as you add it, and simmer until thickened.

When potatoes are cooked, stir the thickened sauce into the soup. Bring to a boil once more, then reduce heat to low.

Stir in cheese. Continue to stir until cheese is melted. Remove from heat and stir in sour cream before serving. Season to taste with salt and pepper.