Wash potatoes, prick and bake at 400 degrees for 1 hour. When done let cool. Cut potatoes lengthwise and scoop out pulp. Melt butter in large saucepan over low heat. Add flour, stirring until smooth. Cook 1 minute, stirring constantly. Gradually add 6 cups milk. Cook over medium heat stirring constantly until mixture is thickened and bubbly.

Add potato pulp, salt, pepper, 2 tablespoons onion, 1/2 cup bacon, 1 cup cheese. Cook until thoroughly heated, stir in sour cream. Add extra milk if necessary for desired thickness. Serve with remaining onion, bacon and cheese. Yield 10 cups.