1. In a large pot, brown the ground beef over medium heat. Drain and set aside.
2. In the same pot, sauté the onions and garlic until tender.
3. Add the chicken broth and potatoes. Bring to a boil, then reduce heat and simmer until potatoes are tender.
4. In a separate saucepan, melt the butter. Stir in the flour and cook for a minute. Gradually whisk in the milk until smooth. Add this mixture to the soup.
5. Stir in the cheese until melted. Add the cooked ground beef back to the pot. Season with salt and pepper to taste. Serve hot.