To make cheddar baked potato soup, whisk 1/3 cup flour and 3 cups milk in a saucepan. Bring to a boil while stirring, and cook for 2 minutes. Add 2 large, baked and mashed potatoes, 1/3 cup cheddar cheese, 1/2 teaspoon salt and 1/4 teaspoon pepper. Stir until cheese is melted, remove from heat, and add 1/2 cup sour cream and 1/4 cup sliced green onions. Cover, and cook for 10 to 12 minutes; garnish with cheese and green onions.
Alternatively, try making cheddar baked potato soup from Food Networks' Sandra Lee. Begin by placing 1 baking potato in the microwave, and cook for seven to eight minutes on high. Remove the potato from the microwave, and set it aside to cool. Cut it into 1/2-inch pieces.
In a medium saucepan, combine 2 10-ounce cans of cheddar cheese soup, 2 1/2 cups low-sodium, canned chicken stock and 1/4 cup real bacon pieces. Bring the mixture to a simmer over medium heat, stirring occasionally. Stir in the cubed potato, and cook for an additional five minutes.
Spoon the soup into serving bowls, and top each bowl with some sour cream and chopped green onions. This recipe makes enough soup to serve six people.