Cheesy Mashed Potatoes Casserole

Recipe Pin
55 minutes
8 servings

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Prepare this delicious Cheesy Mashed Potatoes Casserole recipe ahead of time for a stress-free holiday meal. Simple steps, big cheesy flavor, and THE PERFECT side dish!

Cheesy Mashed Potatoes, with bits of cheese and scallions on the top.

As the leaves turn golden and the air becomes crisp, we all crave the comfort potato recipes provide. Enter baked Cheesy Mashed Potatoes, a hearty casserole: the perfect blend of coziness and flavor, ready to grace your holiday table. This make-ahead marvel will not only save you time but will also become the new favorite of everyone who takes a bite. Make it a ‘loaded mash’ by adding clever and delicious additions such as crisped bacon, browned sausage, or cream cheese!

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Make mashed potatoes ahead of time! Whether it’s a festive holiday feast or a cozy family dinner, this assembly of comforting ingredients layered into a potato bake can elevate any meal to new heights of deliciousness. It’s pictured here with my Beef Tips in Herb and Mushroom Pan Sauce. Additionally, its cheesy goodness complements the creamy decadence of my Creamed Pearl Onions, this Southern Corn Pudding, and, of course, these maple-kissed Brussels sprouts

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Why You’ll Love This Recipe!

·         Creamy Meets Savory – The luxurious combination of sour cream and sharp cheddar provides a creamy texture and familiar and comforting flavor to typical mashed potatoes. 
·         Cheese Galore – If sharp cheddar cheese isn’t in your stars, think outside the box regarding the type of cheese and consider block cream cheese, Monterey Jack, Gouda, or Butterkäse. Regardless of using different cheeses, this casserole becomes a gooey, melty paradise that will satisfy cheese lovers with the absolute BEST mashed potatoes.
·         Herb Freshness – Fresh chives and green onions folded into the potatoes offer a freshness that cuts through the richness and adds flavor. 


Cheesy Mashed Potatoes Ingredients

Gather the following medley of simple yet hearty ingredients, where each plays a tasty role in crafting the best potatoes. This ultimate make-ahead casserole for cheesy whipped potatoes promises to be a crowd-pleaser!

The ingredients required to assemble Cheesy Mashed Potatoes to include russet potatoes, cheddar, sour cream, and chives.
  • Russet Potatoes – Known for their fluffy mash and texture. Opt for Yukon Golds as an alternative.
  • Fresh Chives – Add a mild onion flavor without overpowering the dish.
  • Green Onions – Provide a crisp bite and vibrant color.
  • Unsalted Butter – Gives you control over the saltiness of your dish.
  • Sour Cream – Regular or low-fat, for a rich and tangy taste.
  • Cheese – Shredded cheddar cheese for a punchy flavor; if you prefer a nutty note or mild creaminess, think cream cheese, Gouda, Butterkäse, or any meltable cheese your eaters love.
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See recipe card below for a full list of ingredients and measurements.

Substitutions and Variations

When making substitutions, texture, cooking time, and flavor may change.

  • Leeks or shallots – used in place of green onions; they offer a milder alternative.
  • Greek yogurt or whole milk – protein-rich substitutes for sour cream.
  • Dry-cured ham, prosciutto, or smoked bacon – introduces a salty, savory nuance when lightly crisped before being mixed into the potato mixture.
  • Mix in crispy bacon bits and steamed broccoli florets for a hearty Bacon and broccoli variation.
  • Stir in shredded buffalo chicken and top with blue cheese for a spicy Buffalo Chicken twist.
  • Add roasted garlic cloves and a blend of Italian herbs and fresh parmesan cheese to hot potatoes – yield a fragrant garlic mashed potatoes casserole.
  • Blend in caramelized onions and goat cheese – for a tangy, gourmet version of this casserole.

The Perfect Cheesy Potato Mash!

Four Russet potatoes.

Start with cold water and add Kosher or sea salt before boiling for even cooking and flavor absorption.

I favor Russets for this mashed potato recipe, but Yukon Gold potatoes work well, too.

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Tip: Shred Your Cheese from A Large Block

Block cheese is fresher and melts better; avoid pre-shredded cheese when possible.


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This recipe has not been tested with other substitutions or variations. If you replace or add any ingredients, please let us know how it turned out in the comments below!

Can the Casserole Be Made Ahead?

This scrummy, cheesy potato bake is ideal for making ahead of time. You can prepare the dish up to the point of baking, then cover it tightly with plastic wrap or aluminum foil and store it in the refrigerator for up to 3 days. 

When you’re ready to serve, remove the casserole from the refrigerator, let it sit at room temperature for about 30 minutes, and then bake as directed, adding an extra 10-15 minutes to the baking time since it’s starting from a chilled state. This make-ahead feature makes it a fantastic option for stress-free holiday planning or getting a head start on weekly meal prep.

Step By Step Instructions

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Tip: Potato Prep 101

Cut your potatoes into even sizes for uniform cooking.


Four images showing the steps to prepare potatoes for a Cheesy Mashed Potatoes recipe to include dicing the potatoes, boiling them in salted water, and melting butter for the mash.

Dice and Boil the Potatoes

If planning to bake Cheesy Mashed Potatoes immediately, adjust a rack to the upper-third position and preheat your oven to 350°F. Butter an 8 x 8-inch or a 9 x 9-inch oven-safe dish with 1 tablespoon of butter that has been softened.

Step 1. Begin by peeling and evenly dicing 2 pounds of potatoes into 1 1/2-inch pieces. Potatoes that are cut into uniform sizes will cook at the same rate. (Image 1)

Step 2. Transfer the potato chunks to a large pot. Add 1/2-tablespoon of Kosher salt and enough cold water to cover the potatoes. (Image 2)

Step 3. Boil the potatoes for about 15 minutes, or until fork-tender. When you stab them, there should be no resistance and they should release freely. (Image 3)

Step 4. While the potatoes are boiling, take the opportunity to melt and slightly cool 1/2-cup of salted butter. (Image 4) Set aside.

Four images showing the ingredients required to mash boiled potatoes for a Cheesy Mashed Potatoes recipe to include sour cream, cheddar cheese, and melted butter.

Mash the Potatoes

Step 5. Once your potatoes are cooked, drain them. Return them to the pot. While your burner is off but still hot, shake the pot over the residual heat to hasten excess water to evaporate. When the potatoes are steaming no more, pour in that melted butter! (Image 5)

Step 6. Using a potato masher or hand mixer, begin to break up the potatoes. Alternatively, you may also pass through a ricer. (If ricing, add the butter AFTER the potatoes have been riced). In this step, you are not mashing the potatoes until smooth, rather you want them to remain a bit lumpy. Do not overwork. (Image 6)

Step 7. OPTIONAL. If you prefer a smoother mashed potato, add in 4 to 5 tablespoons of whole milk, buttermilk, or half and half. The addition of milk is not crucial to the recipe, but I like a super creamy casserole, and milk yields that desired texture I am looking for. (Image 7)

Step 8. Add in 1 cup of sour cream, then pick up mashing where you left off, this time whipping until smooth. (Image 8)

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Tip: Use the Right Tool for Mashing Consistency

For smoother potatoes, use a ricer or mixer; for chunkier, stick with a hand masher.


Four images showing flavorful and colorful ingredient additions being added to a Cheesy Mashed Potatoes Casserole right before it is baked to include chives, cheese, scallions, and freshly cracked black pepper and salt.

Flavor the Mashed Potatoes

Step 9. To the mash, add the scallions (green parts only for now), followed by the minced chives. (Image 9)

Step 10. Next, add 3/4-cups of the shredded cheddar cheese (Image 10) followed by several hearty cranks of freshly cracked black pepper. (Image 11) Use a wooden spoon to gently fold all into the mashed potatoes, again paying close attention NOT to overwork. (Image 12)

Four images showing the toppings that are added to Cheesy Mashed Potatoes before being baked which include black pepper, scallions, shredded cheddar cheese, and dots of salted butter.

Prepare the Casserole

Step 11. Scrape the potato cheese mixture into the buttered baking dish and use the back of your wooden spoon to smooth out the surface. (Image 13) Give the surface of the casserole another crank of black pepper across the top of your buttery mashed potatoes (Image 14), the remaining 1/4-cup of shredded cheddar (Image 15), and finally, the white parts of the scallions (Image 16).

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Tip: Ideas Around Leftovers

Leftovers may be smoothed over a Shepherd’s Pie or Cottage Pie recipe, shaped into potato patties or potato cakes and pan-fried, or simply enjoyed reheated alongside your favorite main dish.

Four images showing a woman's hands adding tiny pieces of butter to the surface of a loaded mashed potato casserole ready to be baked, then the delicious looking post bake.

The Bake

Step 12. Use the remaining 1 tablespoon of butter to dot the casserole. (Image 17) Simply cut it into tiny pieces and distribute across the potatoes. (Image 18)

Step 13. Bake the potato casserole for 20 to 25 minutes or until the top begins to turn golden brown, the cheese is bubbling, and the scallions begin to lightly char. (Image 19)

Step 14. Remove the casserole from the oven. The contents will be HOT! Allow the Cheesy Mashed Potatoes to stand for 10 minutes before serving. Then, dig in and enjoy as a side to your favorite meal! (Image 20)

How to Serve a Mashed Potato Bake with Cheese

As a Side Dish

  • Simply spoon it onto plates next to your main protein like roast chicken, steak, or a vegetarian alternative. The cheesy flavor and creamy texture make it a versatile side that pairs well with almost anything.

Under a Gravy

  • If you have gravy as part of your meal, like with turkey or a savory vegetarian gravy, spoon it over the casserole for added moisture and richness.

As a Base

  • Use the casserole as a base for a deconstructed shepherd’s pie—top with a layer of ground meat or lentils in gravy, followed by some fresh veggies.

Family Style

  • Bring the casserole dish to the table as part of a family-style meal, letting everyone dig in and serve themselves.

Buffet Spread

  • If you’re serving a buffet, the casserole can be a hearty option amidst a spread of other dishes, allowing guests to help themselves.

Jenny’s Pro Tips

  • Cold Water Start: Begin boiling your potatoes in cold water to ensure they cook evenly throughout. Starting in hot water can cook the outside too quickly, leaving the inside underdone.
  • Don’t Skimp on the Fat: Fat adds flavor and richness, so use full-fat sour cream and real butter for the best taste and texture.
  • Assembling: If making ahead, let the casserole come to room temperature before baking to ensure even cooking.

Recipe FAQs

How can I prevent my cheesy mashed potatoes from becoming gummy?

Be careful not to over-mash them. Use a hand masher or ricer for the best texture, and add warm melted butter and, if desired, milk or buttermilk gradually while mashing.

Can I make cheesy mashed potatoes without dairy?

Yes, you can make dairy-free cheesy mashed potatoes by using plant-based butter and milk substitutes, along with a vegan cheese that melts well.

How can I thicken runny mashed potatoes?

If your cheesy mashed potatoes are too runny, thicken them by stirring in more cooked potatoes or simmering on low to reduce moisture before baking.

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After trying this recipe, I would love to hear your thoughts! Consider leaving a star rating in the recipe card located below or sharing your feedback in the comment section. Your reviews and comments are highly valued and appreciated.

Recipe

featured image for Cheesy Mashed Potatoes Casserole

Cheesy Mashed Potatoes Casserole

Jenny DeRemer
A savory make ahead cheesy mashed potato casserole that's easy to double or triple, making your holiday cooking to-do's a whole lot easier!
4.92 from 56 votes
Servings: 8 servings
Prep Time 20 minutes
Cook Time 35 minutes
Total Time 55 minutes
Course Side Dish
Cuisine American, Southern
Servings 8 servings
Calories 302 kcal

Equipment

  • 8 x 8-inch or 9 x 9-inch casserole dish

Ingredients
 

  • 4 pounds russet potatoes
  • Kosher salt for salting the potato water
  • 2 tablespoons chives fresh, chopped
  • 1 bunch scallions chopped, white and green parts separated
  • ½ cup + 2 tablespoons unsalted butter divided; 1/2 cup melted, 1 tablespoon softened to grease baking dish, 1 tablespoon cut into tiny pieces
  • * 4-5 tablespoons whole milk * OPTIONAL
  • 1 cup sour cream brought to room temperature
  • 1 cup sharp cheddar or white cheddar cheese divided; may substitute any melty cheese if desired

Instructions
 

  • If planning to bake immediately, preheat oven to 350°F. Butter an 8 x 8-inch or a 9 x 9-inch oven-safe dish with 1 tablespoon of butter. Set aside.
  • ​Peel and quarter the potatoes and add them to a large stock pot or Dutch oven. Add enough COLD tap water to cover by 1/2-inch. Sprinkle with Kosher salt, about 1/2 tablespoon.
  • Bring the pot to a boil and boil the potatoes for about 15 minutes or until a fork stabs without resistance. Drain the potatoes and return to the pot. Place the pot back over the still-warm burner and shake to evaporate excess water.
  • Melt 1/2 cup of the butter. Using a hand mixer or a potato masher, add to the potatoes and mash coarsely. Alternatively, run through a potato ricer. They need not be smooth yet. Add the sour cream. Now mash until smooth. DO NOT overwork the potatoes.  If they feel too stiff, you may add a splash of milk, about 4 to 5 tablespoons, however completely optional.
  • Fold the chopped chives, the green parts of the scallions, and 3/4 cup of the shredded sharp cheddar cheese. Spoon the mixture into the prepared casserole dish. Scatter the remaining white parts of the scallions over the top, along with additional freshly cracked black pepper and the remaining 1/4-cup cheese. Dot the remaining tablespoon of butter over the top of the casserole.

You can bake the casserole now or cover it and refrigerate for a later bake.

  • To bake the casserole immediately, place into the preheated oven and bake for 20 minutes or until the top is lightly golden, the cheese melts, and scallions begin to brown and char.
    If baking the casserole later, pull it from the refrigerator and let it stand while the oven preheats. Place into the oven and bake for 30 to 35 minutes or until lightly golden and scallions begin to brown and char.

Notes

To Freeze: 
For a whole casserole, assemble the recipe following the directions, stopping just before baking it. Assemble in a freezer-safe glass baking dish with a tight-fitting lid or a double layer of aluminum foil. After marking the contents and the date of freeze on the outside, place them flat into the freezer. Freeze for up to three months.
 
For freezing leftover portions which have already been baked, spoon into a freezer-safe plastic container with a tight-fitting lid, then mark with the contents and date of freeze noted on the container. Freeze for up to three months.
 
To thaw and heat: 
Place in the refrigerator overnight.
To heat a whole casserole, once wholly thawed, bake as directed on the recipe card, as it will be being baked for the first time.
For previously baked portions, heat gently in the microwave until hot.

The nutrition value can vary depending on what product(s) you use. The information below is an estimate. Always use a calorie counter you are familiar with.

Please note that table salt and iodized salt are NOT substitutions for Kosher salt. Do not deviate unless otherwise specified.

Nutrition

Serving: 1servingCalories: 302kcalCarbohydrates: 43gProtein: 9gFat: 11gSaturated Fat: 6gPolyunsaturated Fat: 1gMonounsaturated Fat: 2gTrans Fat: 0.01gCholesterol: 33mgSodium: 116mgPotassium: 1014mgFiber: 3gSugar: 3gVitamin A: 405IUVitamin C: 14mgCalcium: 171mgIron: 2mg
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Recipe Rating




24 Comments

  1. Made this Cheesy Mashed Potatoes Casserole for a holiday meal and we all loved it. The cheese made it so gooey and delicious. I mixed in some bacon bits and broccoli and it made a very delish side dish.5 stars

  2. We brought this to a Super Bowl party, and it was gone within 5 minutes. 😆 I got to try a tiny bite, and it was amazing! Nothing beats cheesy potatoes. I’m making it again right now because I need more for myself. 😉5 stars

    1. Hannah, you flatter me! But it’s true that this is a hard dish to keep around on a buffet table. I am known to make this in triplicate when I make it for my Easter buffet. It’s the only way to ensure I get a taste! x – Jenny

  3. Cooked up this cheesy mashed potatoes casserole for a cozy dinner at home, and it was delicious! Used Greek yogurt instead of sour cream for a healthier option, and it was so creamy. Loved the addition of crispy bacon bits, they added a nice crunch to every bite!5 stars