Brown the sausage in a pot, break it into small pieces, then remove and set aside, keeping a little grease.
Melt butter, then sauté onion and garlic for 3–4 minutes until soft.
Add potatoes, broth, seasoning, salt, and pepper. Bring to a boil, then simmer 12–15 minutes until tender.
Whisk flour with milk or half-and-half, then slowly stir into the pot to thicken.
Add heavy cream, cheddar, and sausage. Stir until melted and simmer 5 minutes.
Ladle into bowls, top with parsley or chives, and serve warm.