Cheesy Mashed Potato Casserole

Try this cheesy mashed potato casserole for when you are looking for a way to make instant mashed potatoes into something tastier.  This recipe for Cheesy Mashed Potato Casserole combines mashed potatoes, sour cream, herbs, cheese, and more! , this recipe was created out of necessity, no time to shop, and a few ingredients will make for a unique side dish. Sour cream, french fried onion rings, seasonings, and some cheddar cheese make this a potato dish that people will ask for your Cheesy Mashed Potato Casserole, and it can be made in under 30 minutes.

mashed potatoes topped with Cheddar cheese, baked in the oven and topped with frenchs onion rings

Try this cheesy mashed potato casserole when you are looking for a way to make instant mashed potatoes into something tastier. This casserole combines mashed potatoes, sour cream, herbs, cheese, and more. It’s a recipe that was created out of necessity – no time to shop and a few ingredients on hand made for a unique side dish. Sour cream, fried onion rings, seasonings, and some cheddar cheese make a potato casserole that your family will ask for again and again.

What About Using Fresh Potatoes?

I must confess that sometimes I use instant mashed potatoes and have fed them to my guests. Most people won’t even know the difference if you add a few extra ingredients to the potatoes. When making instant mashed potatoes, I always use a little extra butter, and I will swap the milk for some half-and-half if I have it available – these two ingredients will make the potatoes nice and rich. Let me just say that you can, of course, make this dish with fresh potatoes. I would use about two pounds of potatoes when making this dish from scratch.

A Brief History of the Potato

The Incas in Peru were the first civilization to cultivate potatoes around 8,000 – 5,000 B.C. After the Spanish Conquistadors conquered Peru in 1536, they discovered potatoes and brought them to Europe. Potatoes landed in the US in 1621 when Nathaniel Butler, the Governor of Bermuda, sent vegetables, including potatoes, to the Jamestown colony in Virginia. Farmers everywhere eventually discovered that potatoes were easy to grow and in time it became known that potatoes contained nearly all of the vitamins necessary for human sustenance. You can read much more about the long history of the potato.

Mashed potato cassersole topped with cheese and Frenchs onions

Some Interesting Facts About Potatoes

In the 18th Century Antoine-Augustin Parmentier, a French pharmacist convinced the French to eat potatoes and saved thousands from starvation during the European famines in the 1700’s. In 1767, Parmentier created a feast for King Louis XIV that consisted solely of potato dishes, a concept he realized was possible after being imprisoned in Germany and fed only on a diet of potatoes. Benjamin Franklin, the American Ambassador to France, attended Parmentier’s feast

  • During the Klondike gold rush in Alaska, (1897-1898), gold miners paid for potatoes in gold. Gold was plentiful but nutritious vegetables weren’t.
  • In 1995, the potato starred as the first vegetable to be grown in space. NASA and the University of Wisconsin created a technology that would enable astronauts to be fed on long space voyages. It is hoped that in future potatoes will help feed human colonies on distant planets.

Sour cream, Cheddar cheese, Frenchs onions, parsley, chives, and black pepper

Love Mashed Potatoes? Be sure to check out these mashed potato recipes.

mashed potato casserole with cheese and crispy fried onions on top.

Mashed Potato Casserole

This cheesy mashed potato casserole is so hard to resist. Break out those French fried onions and upgrade your mashed potatoes.
5 from 4 votes
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Course: Side Dish
Cuisine: American
Keyword: mashed potato casserole, Potato Recipes
Prep Time: 10 minutes
Cook Time: 20 minutes
Total Time: 30 minutes
Servings: 8
Calories: 236kcal


  • 4 cups instant mashed potatoes
  • 3/4 cup sour cream
  • 1 teaspoon dried chives
  • 1 teaspoon dried parsley
  • 1/2 teaspoon black pepper
  • 3/4 cup shredded cheddar cheese
  • 1 cup French's Crispy Fried Onions


  • Preheat the oven to 350°F.
  • Prepare the instant mashed potatoes according to the package directions.
  • Add sour cream, chives, parsley, and pepper.
  • Place the mashed potatoes in a 1 1/2-quart casserole dish.
  • Top with cheddar cheese.
  • Sprinkle French's Fried Onions around the edge of the casserole.
    If you are making this dish ahead to reheat later, add the shredded cheese, but wait to top with French’s Fried Onions until you are ready to reheat.
  • Bake for about 20 minutes or until the cheese melts.


Calories: 236kcal | Carbohydrates: 28g | Protein: 5g | Fat: 11g | Saturated Fat: 6g | Cholesterol: 22mg | Sodium: 173mg | Potassium: 388mg | Fiber: 2g | Sugar: 1g | Vitamin A: 660IU | Vitamin C: 28.5mg | Calcium: 113mg | Iron: 0.6mg

About Stephanie Manley

I recreate your favorite restaurant recipes, so you can prepare these dishes at home. I help you cook dinner, and serve up dishes you know your family will love. You can find most of the ingredients for all of the recipes in your local grocery store.

Stephanie is the author of's Dining Out in the Home, and's Dining Out in the Home 2.

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Reader Interactions


  1. Laurie

    I would like to make the Cheesy Mashed Potato Casserole but what do you mean by 4 cups instant mashed potatoes? Does that mean 4 cups of the potato flakes and then follow package directions or 4 cups of prepared instant mashed potatoes? Sorry if question is dumb but I am still in training when it comes to kitchen duty. Thank you.

  2. Tomtom

    5 stars
    This was a potato casserole my mother-in-law enjoyed, which was surprising. She is very picky, and has told me that plain baked potatoes with nothing on them are “too salty”. Sometimes I stare at her and think my husband must have been adopted.

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