1/3 cup butter
1 small onion, diced (about 1 cup)
1 1/4 cups chicken broth
1 1/2 cups milk (1%, 2% or whole)
4 cups left-over mashed potatoes
1/2 cup sour cream (I used light)
sliced green onion, if desired
cooked, crumbled bacon, if desired
shredded cheddar cheese, if desired

1. Heat a medium pot over medium heat until hot. Add the butter and let it melt. Add the onion and cook, stirring often, until it's starting to brown, 5-8 minutes. Add the chicken broth and milk, and scrape any browned bits off the bottom of the pot.

2. Add the mashed potatoes and stir/whisk the soup gently to "melt" the mashed potatoes into the liquid. Bring the soup to a simmer, reduce the heat, and gently simmer for 5 minutes. Stir in the sour cream and heat it through. Don't let the soup simmer after adding the sour cream because it will separate and your soup's texture and appearance will suffer. **I want my soup to be able to stand up to the toppings. If your soup seems too thin after simmering for 5 minutes, go ahead and simmer it a little longer, just make sure you do it before adding the sour cream.**

3. To serve, top individual bowls with the cheese, bacon, and green onion.
Makes 4-6 servings.