Add butter to pan, once melted whisk in flour and cook for 2-3 minutes until bubbly. Whisk in milk and one cup of broth. Bring to a boil, stirring continuously. Add additional broth to achieve desired thickness. Add garlic, seasonings, and precooked potatoes. Simmer soup gently for 10 minutes or until potatoes are tender.
Serve topped with crispy bacon, scallion slices, and shredded cheddar cheese.