Elsie’s Baked Potato Soup

Instructions
Preheat oven to 400 degrees. Prick potatoes with a fork to allow for venting during roasting and bake for one hour or more until potatoes are fully cooked.
Cool slightly, peel away the skins and dice the interior. Set aside 1 cup diced potatoes.
Combine the chicken broth and milk in a medium heavy saucepan and heat just until warm, but not scalding. Hold over low heat, watching to prevent scalding.
Melt butter in a large, heavy saucepan. Add chopped onions and cook until the onions are slightly translucent. Stir in flour and cook over medium heat, stirring constantly for three minutes.
Gradually pour in hot milk/broth mixture, whisking during each addition to prevent the sauce from lumping. Cook over low heat until the sauce begins to thicken. Mash the reserved 1 cup of potato into the sauce and cook, stirring, until the mixture is the consistency of heavy cream.
