Baked Potato Soup

4 large baking potatoes
2/3 cup butter or margarine
2/3 cup flour
6 cups milk
3/4 tsp salt
1/2 tsp black pepper
1/2 tsp white pepper
4 green onions, chopped and divided
12 slices bacon, cooked and crumbled
1 1/4 cups cheddar cheese, shredded and divided
8 ounces sour cream

Wash, dry and prick potatoes with fork. Bake in 400-degree oven for 1 hour or until done. Let cool. Cut into half lenghwise and scoop out pulp; set aside. Use skins for something else, such as stuffed potato skins. Melt butter in heavy saucepan over low heat; add flour, stirring until smooth. Cook 1 minute, stirring constantly. Gradually add milk, cook over medium heat, stirring constantly until mixture is thickened and bubbly. Add potato pulp, salt, pepper, 2 Tbs. green onion, half the bacon and 1 cup cheese. Cook until thoroughly heated. Stir in sour cream. Add extra milk if necessary for desired consistency. Serve with remaining green onions, bacon and cheese.