In a large pot, brown the ground beef over medium heat until cooked through; drain fat and set meat aside.

In the same pot, melt 1 tablespoon of butter and sauté the onion, carrots, celery, basil, and parsley until vegetables are tender, approximately 5 to 7 minutes.

Add the chicken broth, diced potatoes, and the cooked ground beef back into the pot.

Bring the mixture to a boil, then reduce heat to low, cover, and simmer for 10-12 minutes or until potatoes are tender.

In a separate small skillet, melt the remaining 3 tablespoons of butter. Whisk in the flour and cook for 1 minute to create a roux.

Gradually whisk the milk into the roux until smooth, then stir this mixture into the soup pot.

Bring the soup to a gentle boil and cook for 2 minutes while stirring until the liquid thickens.

Reduce heat to low and stir in the shredded cheddar cheese until completely melted.

Remove from heat and stir in the salt, black pepper, and sour cream before serving.