In a large pot over medium heat, cook the ground beef. Drain, and set aside.
Melt the butter in the pot and add in the carrots, celery, and onions. Saute until tender, 5-7 minutes.
Stir in garlic, and cook an additional minute. Add potatoes, beef, chicken stock, and spices.
Cover and simmer for 10-12 minutes.
Whisk together the milk and flour. Stir into the soup, and cook for 10 minutes.
Stir in the cheeses until melted. Turn off the heat, and stir in the sour cream.
Serve with crumbled bacon, onion rings, and green onions!