2 tablespoons butter or margarine
2 tablespoons flour
2 cups milk
1 to 2 cups mashed potatoes
Chopped onions to taste or onion powder to taste
salt and pepper to taste

In a saucepan over medium heat, melt butter. Stir in the flour and stir to create a paste. Add the milk and continue to stir until the white sauce thickens. Add the onion and salt and pepper. Add the mashed potatoes and stir until smooth. You may need to experiemect with the amount of milk to the amount of mashed potatoes until you get thickness you want. I also sometimes add dumplings to the soup. To make the dumplings: beat 2 eggs, add flour a little at a time until the "dough" hold together (should be a little moister than homemade noodle dough). Drop by the rounded teaspoon into the soup and allow to cook until cooked clear through (about 10 minutes).