Houlihan's Baked Potato Soup

1 1/2 lbs baking potatoes
2 cups yellow onions, diced
5 cups water
1 cup instant potato flakes
1 cup milk
1/4 lb butter
1/3 cup flour
1/4 cup chicken base
1 cup heavy cream

Preheat oven to 400 degrees.  Prick washed potatoes and bake until fork pierces to the center easily.  Remove potatoes from oven and allow to fully cool.  Remove skin and cut potatoes into 1/2" cubes.  Set aside.  Melt butter in a  large saucepan.  Add onions and sautee over low heat for 10 minutes or until onions are translucent.  Don't allow onions to burn.  Add flour to onions and butter and cook 4 to 5 minutes stirring well until flour is absorbed.  In a separate container, combine water, chicken base, and potato flakes.  Stir or whisk to eliminate lumps.  Add slowly to pinion mix, stirring so no lumps form.  Increase heat and continue cooking until soup begins to gently simmer.  Add milk and cream, stirring until smooth and slightly thickened.  Simmer 15 minutes, do not boil.  Add cubed potatoes and stir to combine.  Remove from heat and serve.  Top each serving with grated cheese, sliced scallions, and bacon pieces.