Bake potatoes until tender; cool.  Peel (optional) & cube.  In large pan, melt butter; stir in flour, salt & pepper until smooth.  Gradually add milk.  Bring to a boil, cook & stir for 2 minutes or until thickened.  Remove from heat.  Whisk in sour cream.  Add potatoes, onions, bacon & cheese.  (I put it all in a crock pot & heat through.)