Take some of the stress out of serving a big holiday meal to a large group of people (or any meal for that matter) by preparing this cheesy horseradish mashed potato side in advance. Then pop it into the oven about an hour before you're ready to eat! Now it's time to relax before dinner. You've earned it!

This make-ahead holiday side dish is always a hit with its zippy cheesy flavor and hot creamy texture.
If you'd like to spend more time with the people you care about and less time in the kitchen, then this make-ahead cheesy horseradish mashed potato casserole needs to be on your holiday menu this year.
Roasted Baby Potatoes are another potato side dish I know you'll love!
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- Roasted Baby Potatoes are another potato side dish I know you'll love!
- The ingredient list:
- Kitchen tools and equipment:
- Why are russet potatoes the best for mashing?
- Why should I start my mashed potatoes in cold water?
- When making mashed potatoes, always remember to:
- Add-ins suggestions for your make-ahead mashed potato casserole you may want to try:
- What is the best way to reheat this mashed potato casserole after it's been refrigerated?
- How much ahead can I make this holiday side dish?
- Can this make-ahead side dish be frozen?
- The step-by-step photo instructions:
- What to serve alongside these make ahead mashed potatoes
- Printable Recipe Card
- Make-Ahead Cheesy Horseradish Mashed Potato Casserole
The ingredient list:
**Note - The following lists of ingredients plus kitchen tools and equipment contain affiliate links (highlighted in blue) for your consideration and shopping convenience. #CommissionsEarned
- Russet Potatoes
- Whole Milk or Evaporated Milk
- Butter
- Prepared Horseradish
- Cream Cheese
- Cheddar Cheese
- Salt and Pepper
- Grated Nutmeg
Kitchen tools and equipment:
- Large Stock Pot
- Measuring Cups and Spoons
- Potato Masher or Potato Ricer
- Cheese Grater or Box Grater (optional)
- Nutmeg Grater
- 13" x 9" Casserole Dish
- Non-Stick Cooking Spray
- Aluminum Foil
Why are russet potatoes the best for mashing?
Russet potatoes have a very high starch content making a fluffier and more flavorful mashed potato.
Another good high starch potato choice for this mashed potato casserole is the Yukon gold potato if you happen to prefer those over russet potatoes.
Why should I start my mashed potatoes in cold water?
Always start cooking the peeled and cubed potatoes in cold water.
It may seem counter-intuitive, but starting the potatoes in hot water will risk the chance of them being cooked unevenly, leaving some thoroughly cooked and some not.
You always want all your potatoes to be perfectly cooked at the same time.
When making mashed potatoes, always remember to:
- Start them in cold water
- Generously salt the cooking water
- Drain the potatoes thoroughly after cooking
- Add the drained potatoes back into the hot pot
- Warm the milk before adding it to the potatoes for better absorption.
- Always add room temperature butter, cream cheese, and shredded cheese for better blending
- Use a potato ricer for creamier potatoes
Add-ins suggestions for your make-ahead mashed potato casserole you may want to try:
- Cooked Bacon
- Scallions
- Caramelized Onions
- Shallots
- Pepper Jack Cheese
- Green Peas
- Diced Ham
- French Fried Onions
- Gravy
- Boursin Cheese
- Mozzarella Cheese
- Parmesan Cheese
What is the best way to reheat this mashed potato casserole after it's been refrigerated?
The most important thing is to allow the potato casserole to sit at room temperature for 60 minutes before baking.
Then bake the covered casserole in a preheated 350-degree oven for 45 minutes, remove the cover and cook for an additional 15-20 minutes until the potatoes are hot and steamy all the way through.
How much ahead can I make this holiday side dish?
You can make this up to 3 days before serving.
To store, allow the casserole to cool completely, cover tightly with foil or plastic wrap, and refrigerate.
Can this make-ahead side dish be frozen?
Yes!
Allow the potatoes to cool completely before freezing. Cover the casserole dish well with foil or plastic wrap and freeze for up to 2 months.
Thaw completely before heating in a 350-degree oven for 50 minutes, covered, and 15 minutes uncovered.
Stir the potatoes thoroughly before serving when you're reheating after freezing.
The step-by-step photo instructions:
- Peel and dice the potatoes into approximately 1½" cubes.
- Place the potatoes in a large stockpot and add enough cold water to cover.
- Allow the butter and cheeses to come to room temperature.
- Salt the potato cooking water liberally, and cover the pot.
- Bring the potatoes to a low boil (keeping an eye on them so they don't boil over). Approximately 20 minutes.
*NOTE - Keeping a wooden spoon in the pot while the potatoes cook will keep the cooking water from boiling over.
- Once the potatoes are fork-tender, carefully drain the potatoes and immediately add them back into the hot pot.
- Add the room-temperature butter, cream cheese, salt, pepper, and warm milk to the cooked potatoes.
- OR, if using a ricer, rice the potatoes before adding the remaining ingredients.
- After the butter, milk, cream cheese, and seasonings are mashed in, add in the prepared horseradish, shredded cheddar cheese, and grated nutmeg.
- Spoon the mashed potatoes evenly into a prepared casserole dish that has been sprayed with cooking spray.
- Cool the potatoes completely (if making them in advance), and cover well with aluminum foil or plastic wrap.
- Keep refrigerated for up to 2 days, or freeze for up to 2 months.
- If serving the same day, add the mashed potato casserole immediately into a preheated 350-degree oven and heat for 20 minutes.
Click here to visit my most popular Thanksgiving Side Dish recipe roundup post!
These pretty and easy Duchess Potatoes look like roses and will be the star of any dinner plate. What makes them even better is that they can be made using leftover mashed potatoes. Talk about an impressive way to serve leftovers!
What to serve alongside these make ahead mashed potatoes
You'll be amazed at how delicious Brown Bag Roast Turkey is! The skin is crispy, and the meat juicy! It’s utter perfection!! This method for roasting a Thanksgiving turkey has it IN THE BAG so don't miss out your chance to serve the best roast turkey you've ever had!
You can have this impressive Bacon Bourbon Green Bean Almondine side dish on the table in under 30-minutes. It's fancy enough to serve for the holidays and yet it's easy enough to make any night of the week.
When you make this recipe, and I hope you do, I'd appreciate it if you'd take a moment to leave a star rating on the recipe card and briefly comment on why you rated it as you did. FYI - Google appreciates recipe ratings and, in turn, will share my recipes with more people. Thank you so much!!
Printable Recipe Card
Make-Ahead Cheesy Horseradish Mashed Potato Casserole
Ingredients
- 5 pounds of russet potatoes peeled and cut into 1½" cubes
- 2 tablespoons salt
- 3 quarts water
- 1 cup warm milk
- 8 tablespoons butter at room temperature
- ½ cup prepared horseradish or to taste
- 4 ounces cream cheese softened
- 8 ounces shredded sharp cheddar cheese at room temperature
- 1 teaspoon coarse ground black pepper
- ¼ teaspoon freshly grated nutmeg or to taste
Instructions
- Add the prepared potatoes to a large stockpot and cover with cold water.
- Cover the pot with a lid.
- Bring the water to a low-boil and add 2 tablespoons salt. *Note - keeping a wooden spoon in the pot will stop any boilovers.
- Reduce the heat slightly and simmer the potatoes until fork-tender (approximately 30 minutes).
- Drain the potatoes and add them back into the hot pot.
- Add the warm milk, room-temperature butter, and cream cheese into the potatoes and mash.
- *Note - if ricing the potatoes, after draining, rice them into the hot pot and then add the remaining ingredients to the riced potatoes and stir.
- Add the horseradish, shredded cheese, black pepper, additional salt (if desired, to taste) and grated nutmeg.
- Mash again until you reach your desired consistency.
- Add the cheesy horseradish mashed potatoes into a 13x9 casserole dish which has been sprayed with baking spray.
- To refrigerate: Cool Completely. Cover with foil or plastic wrap and refrigerate for up to 2 days.
- To freeze: Cool Completely. Cover with foil or plastic wrap and freeze for up to 2 months.
- If serving immediately, place in a preheated 350-degree oven for 20 minutes, uncovered.
Notes
Nutrition
I sincerely hope you've enjoyed this delicious make-ahead holiday mashed potato side dish recipe as much as I've enjoyed bringing it to you.
Kudos Kitchen by Renee – Where I joyously bring you easy, economical, and delicious comfort food dishes to feed the people you love!
Until we eat again, I hope you have a delicious day!
Brittany says
I never thought of adding horseradish to mashed potatoes! I especially love how this dish can be made in advance. It will be perfect to bring to my aunt's thanksgiving party this year! Thank you for sharing, I can't wait to try this recipe!
JulieD says
Such a great idea, Renee! Thank you so much for joining in!!