1. In a large heavy-bottomed pot, cook bacon until crisp; remove bacon; and drain on paper towels, reserving 1 tablespoon drippings in pot. Crumble bacon.
2. Cook green onion in hot drippings over medium-high heat for 3 minutes, or until tender. Add broth. Whisk in sour cream and milk. Add potatoes, salt, and pepper. Cook for 15 minutes, or until heated through. Top with crumbled bacon, and, if desired, garnish with shredded Cheddar cheese, chopped chives and sour cream.