Cook bacon in Dutch oven until crisp. While bacon is cooking, peel and cur potatoes into 3/4 inch cubes. Transfer cooked bacon to paper towels. Add onion to bacon grease and cook until tender. Add garlic and flour and cook about one minute. Slowly whisk in broth and cream, then thyme and potatoes, bringing to a boil. Reduce heat to medium low, cover pot and cook until potatoes Rw tender, about ten minutes. Discard thyme and transfer two cups of drained potatoes to a bowl. Using a blender or food processor, puree remaining soup in batches until smooth. Return pureed soup and reserved potatoes to pot and warm. Turn off heat and add cheese, one cup at a time, allowing cheese to melt before adding more. Add sour cream and stir until well blended. Ladle into bowls and garnish with bacon, extra cheese and sour cream, and scallions.

Lower fat version: Use turkey bacon and cook onion in olive oil. Substitute reduced fat sour cream and cheddar cheese (do not use fat free versions). Use half and half instead of heavy cream.