Baked Potato Soup
If using bacon, fry it over medium heat until crisp. Remove and set aside. Crumble it when it is cooled.
In a large kettle, melt the margarine over medium heat. Whisk in the flour until smooth. Gradually stir in the milk, whisking constantly until thickened. Stir in potatoes and onions and bring to a boil, stirring frequently.
Reduce heat and simmer for 10 minutes. Add the bacon, cheese, sour cream, salt and pepper. Stir until cheese is melted. Serve immediately.