Leftover Mashed Potato Soup

Are you asking yourself what to do with leftover mashed potatoes? Well, I have a delicious idea for you: Leftover Mashed Potato Soup. Made from whole food ingredients, this delicious soup transforms your lumpy leftover mashed potatoes into a hearty, filling soup. Perfect for Thanksgiving and Christmas leftovers.

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When it comes to mashed potatoes, I am obsessed. If you were to ask me what I would have for my last meal if given the choice, a nice big serving of mashed potatoes is sure to make the cut. Since I love potatoes so much, I'd probably have a big baked potato with butter, salt, pepper, and real sour cream too, just for good measure. 😋

Mashed potatoes are a favorite of many, no matter the time of the year. When it comes to the Holiday season though, their popularity increases even more so. With many many pounds of mashed potatoes being prepared from Thanksgiving to New Years, you're bound to have some leftovers along the way. As wonderful as mashed potatoes are, they are kind of lumpy and awkward as leftovers.

Enter this delicious Leftover Mashed Potato Soup

A Recipe for Leftover Mashed Potatoes

In searching for a recipe to use up my leftover mashed potatoes, I found all kinds of references to potato pancakes and shepherd's pie, but I just wasn't feeling the same old same old. I'm one of those people who flip through cookbooks and read them like you would a big fat novel. On this particular day, I was doing this with my More-with-Less Cookbook (a favorite). I often find inspiration for from-scratch, low cost meals from this cookbook, and on this day, as providence would have it, I found a recipe for a mashed potato soup.

The original had less milk, less cheese, and less potatoes. I do more. Always more. When it comes to milk? More. Cheese? Definitely more. Potatoes? Bring it on! So after adjusting it significantly, I happened upon a delicious use of leftover mashed potatoes that would fill and satisfy my family for a quick lunch, or a light supper with some sourdough bread on the side.

Soup: A Lunch Time Favorite

We cook three meals a day completely from scratch. This includes lunch, which can be a bit of an awkward meal to prepare since it is smack dab in the middle of the day. I love making soups for lunch because:

• I can prepare a large batch and reheat through the week
• It's a great way to get vegetables into our mid-day meal
• Soups are inexpensive
• A great way to use up my homemade bone broth or homemade chicken broth.
• A great way to avoid processed foods, since they tend to be lunch time standbys

How To Use Up Leftover Mashed Potatoes

In addition to making this soup, there are a few other ways you can use leftover mashed potatoes!

Some recipes that use leftover mashed potatoes:

• Cheesy Leftover Mashed Potato Pancakes - Just a Taste
• Parmesan and Herb Potato Pancakes - Natasha's Kitchen
• Classic Shepherd's Pie - The Wholesome Dish
• Cheesy Leftover Mashed Potato Muffins - Just a Taste
• Leftover Mashed Potato Bake - Fountain Avenue Kitchen

What Do I Need to Make Leftover Mashed Potato Soup?

• Leftover Mashed Potatoes: Of course you need leftover mashed potatoes! My favorite mashed potatoes to make for guests is this one from Pioneer Woman. You can make it the day ahead and it's always creamy and delicious. I used plain ol' mashed potatoes in this recipe, but I bet Ree's would be a real treat!
• Whole Milk: I always use whole milk, but it's especially important in a soup because it adds a nice creaminess that you don't get with lower fat milks.
• Cheese: Cheddar cheese, shredded fresh from the block will be the best in this recipe. Using cheese from the block means you're skipping out on the additives in pre-shredded cheese, and it melts a lot better too. Not to mention being more cost effective!
• Bone Broth: 2 cups of chicken bone broth is used in this recipe. I freeze my Instant Pot Bone Broth in 2 cup and 4 cup portions, so this is perfect for using in this recipe.
• Onion: Just a little bit of onion for flavor. You'll barely notice it!
• Butter: Just a little bit of salted butter is used, along with flour, to make a roux. This will help thicken the soup so it is more like a chowder.
• Flour: I use all purpose unbleached in this recipe.
• Seasonings: All you need is mineral salt, ground black pepper, and some parsley!

Equipment:

• Dutch Oven or Heavy Saucepan: I love using a dutch oven for soups, since the heavy bottom ensures that it doesn't scorch the bottom.
• Hand Blender: If you like a really smooth soup, a hand blender makes easy work of blending all the potato chunks in the soup until smooth and creamy. This is one of my favorite kitchen tools.

How Do I Make Mashed Potato Soup?

1. Melt the butter in a large saucepan over medium heat. Add the onions and sauté, stirring frequently until the onions are soft and slightly browned
2. Add the flour, salt, pepper, and parsley flakes. Whisk well, and cook, whisking nearly constantly, for about 2 minutes.
3. Slowly add the chicken broth, whisking as you pour it into the saucepan.
4. Increase the heat to medium-high heat and bring the mixture to a boil, stirring often. Let the mixture boil for about 2 minutes.
5. Reduce the heat to medium heat and add the leftover mashed potatoes. Break up the chunks of mashed potatoes using a potato masher or a fork.
6. Once the potatoes are combined, add the milk and stir well.
7. Once the milk is heated through and a soft simmer has begun, add in the cheddar cheese and stir until the cheese is completely melted.
8. Remove from the heat and serve with additional shredded cheddar cheese for topping.

Scroll down for the printable recipe!