Mashed Potato Casserole is an outrageously delicious yet highly practical way to make mashed potato ahead of time! A layer of cheese and bacon prevents the mash from drying out as it reheats in the oven, while transforming this humble side into something extra-devilish and decadent. Oh the power of cheese (plus bacon)!
Make it fresh, or assemble ahead and reheat when required. Serve in place of plain ole’ mash.
Make-ahead mashed potato
With the holidays fast approaching, I thought it would be timely to share my favourite way to make mashed potato ahead of time.
The thing with make-ahead mash is that you cannot simply reheat it in the microwave or oven. You might think a splash of milk and good stir is all it takes to restore it. But I can tell you that’s the path to a mouthful of gluey horridness.
While there are nifty ways to reheat cold mashed potato successfully*, a big dish of creamy Mashed Potato Casserole takes the prize for the most foolproof-yet-show-stopping way I know! It also wins the prize for the lowest effort on the day-of because you literally just pop the pre-assembled dish into the oven. It’s a win-win, 10/10 – nothing could be more fitting for your holiday feast menu!!
* How I reheat plain mashed potato: Cold mash in hot cream (recipe here, but note it’s more work on the day) or in heavy duty piping bags submerged in boiling water, a trick caterers use (see my demo here on Instagram).
Is there such a thing as too much bacon??
Confession: I think I was a little heavy-handed with the bacon in the photos while being a tad short on the stuff for the recipe video!! So the recipe card as written is a happy medium. 😊
But actually, looking at the photo below, it does look pretty enticing with almost full bacon coverage on the surface. And … is there even such a thing as too much bacon?? (Yeah nah)
What you need for Mashed Potato Casserole
Here’s what you need to make Mashed Potato Casserole:
Potato – Floury and all-rounder potatoes work best to achieve a fluffy yet creamy mash without fussing with potato ricers and other gadgets.
– Australia: the cheap dirt-brushed potatoes sold everywhere (called Sebago) are ideal
– US: Russet
– UK: Maris PiperMilk – Our liquid to loosen the potato up to form mash. If making ahead, we add extra (see How To Make section for more).
Sour cream – I prefer using sour cream rather than cream in mashed potato casserole because the slight tang makes a nice counterpoint to all the other richness going on here (butter, cheese, bacon). It doesn’t make it sour in the least. It sort of adds creaminess into the mash without adding cloying richness. Does that makes sense??
Butter – Mash without butter is not mash. #strongopinions!
Cheese – I use a combination: Mozzarella for excellent melty-cheesy-stretchiness. Then Red Leicester for flavour (it’s savoury and a bit sharp, like aged cheddar), and to add a lovely orange hue to the mash surface. If you’re in the States, your orange cheddar is ideal here.
Otherwise, use any melting cheese you like (colby and Monterey Jack are other personal favourites). If you opt to use mozzarella as your main cheese, add a handful of parmesan for flavour because mozzarella alone is actually quite bland and lacks saltiness.
Shred your own – One of my five non-negotiable rules stated loudly on the first page of my cookbook is, “Always shred your own cheese”! Store-bought pre-shredded cheese is coated in anti-caking agents which prevent it from melting as well as freshly-grated. I use a standard box grater for the work.
Pack your cups of cheese – For consistency I prefer weight over volume to measure cheese. So I’ll weigh a hunk of cheese before grating it. But if you are using cup measures, be sure to pack your cups tightly when measuring the shredded cheese otherwise you will be short. Nobody wants to be short on cheese, ever!Bacon – For sprinkling over the casserole surface. Note: I always use streaky bacon. Because fat = flavour! Also, fatty bacon crisps up and colours better, without drying out.
Green onion – For a touch of oniony freshness and colour.
How to make Mashed Potato Casserole
No rocket science here. We make mash, spread it into a casserole dish, top with cheese, bacon and then stop here if making ahead. Finally, on the day of your do, bake it!
Cut potatoes – Peel and cut the potatoes into even sized pieces.
Boil until soft – Place the potatoes in cold salted water. Bring it up to a boil over high heat then reduce the heat down to medium high or medium so it is simmering rapidly. Cook for 15 minutes (no lid) or until the potatoes are very soft. They should fall apart when you jab it with a fork.
Mash – Drain the potatoes well in a colander and pour them back into the empty pot. Mash with the butter, milk, sour cream and salt.
MAKE-AHEAD ADJUSTMENT – If you are making this dish with the intention of serving it the next day, then add an extra 2/3 cup milk. The mash will seem too loose, but this is intentional. It is to factor in the fact that mashed potato firms up when refrigerated overnight. So once reheated, it has the same consistency as when it is freshly made!
Potato masher – I like to use a potato masher that is like a round disc with holes in it, as pictured above. It’s the fastest and most effective tool for a smooth mash without using a potato ricer (which I reserve just for Paris Mash, when seeking that next-level-luxe, ultra-smooth, 3-Michelin-restaurant result!).
Spread in a casserole dish.
Top with the cheeses and bacon. (Yes you eagle-eyed spotters, I was short on bacon for these shots 😂)
For make ahead – At this stage, the assembled dish can be popped in the fridge for up to 3 days. Just take it out of the fridge 2 hours ahead so it has time to de-chill. This will make it reheat faster and more evenly in the oven.Cover with foil then bake for 20 minutes at 200°C / 400°F (180°C fan), if freshly made. Add an extra 15 minutes if you’re reheating a make-ahead casserole you prepared the day before.
Uncover – Remove from the oven and bake for a further 10 minutes until bubbly and golden.
Voila, ready to serve! Crack through that molten cheese surface and marvel at how creamy the mash underneath is!
How to serve Mashed Potato Casserole
This is a dish designed to be a side. (I know we can all picture it moonlighting as a standalone dish after a big night on the turps or a shocking day at work, but it’s meant to take the place of traditional plain mashed potato, I swear.) Because actually, though this has cheese and bacon on it, underneath is all creamy plain mashed potato.
So place it on the table or on the buffet alongside the mains and let everybody dig in and help themselves! Try to get in first though. Because you know full well the first in line are going to take more than their fair share of that cheese bacon topping – and we know full well we also cannot blame them….. – Nagi x
Watch how to make it
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Mashed Potato Casserole
Ingredients
- 1.75kg/ 3.5 lb potatoes (Sebago (Aus), Russet (US), Maris Piper / King Edwards (UK)(Note 1)
- 1 tbsp cooking / kosher salt , for cooking potatoes
- 2/3 cup milk (preferably full fat/whole milk but lite ok)
- 2/3 cup EXTRA milk , for make-ahead option only (Note 2)
- 75g / 5 tbsp unsalted butter , cut into 1cm / 1/2″ cubes
- 1/2 cup sour cream (or yogurt), full fat best
- 1 tsp cooking/kosher salt , or to taste
- 1 1/2 cups (tightly packed) mozzarella , freshly shredded (Note 3)
- 1 cup (tightly packed) Red Leicester, cheddar or other flavoured cheese(Note 3)
- 200g / 6 oz bacon (streaky), chopped (Note 4)
- 1/4 cup green onion , finely sliced
Instructions
Cook bacon:
- Place bacon in a cold non-stick pan over medium heat (no oil). As the pan heats up the bacon fat will melt. Once you see some melted bacon fat, turn the heat up to medium high and stir for 3 minute or until golden.
- Drain on paper towels.
Mash:
- Potatoes – Peel then cut into 3cm /1" chunks.
- Boil – Place in a large pot and cover with water so it’s 10cm / 4” above the potatoes. Add 1 tablespoon salt. Bring to a boil over high heat then reduce heat so it’s simmering rapidly. Cook 15 minutes or until potatoes are very soft (jab with fork to test, they should fall apart).
- Drain well, then return into pot. Leave for 1 minute, shaking pot every now and then, to encourage evaporation of water.
- Mash – Add milk (including EXTRA milk if making-ahead), butter, sour cream and 1 tsp salt. Mash until smooth. (Do not use food processor, blender or beater, makes it gluey!)
Make-ahead directions:
- Fridge – Allow to fully cool on the counter then cover tightly with cling wrap and refrigerate.
- Dechill – Take out onto counter 2 hours prior to reheating.
Assemble:
- Preheat oven to 200°C / 400°F (180°C fan).
- Spread the potato in a 2 litre / 2 quart baking dish (Note 5). Smooth the surface.
- Sprinkle – Sprinkle potato with the cheeses, then bacon.
- Bake covered – Cover loosely with foil. Bake for 20 minutes covered (if freshly made) or 35 minutes (make-ahead option).
- Bake uncovered – Remove foil then bake a further 10 minutes until the cheese is bubbly and golden.
- Serve – Sprinkle with green onion then serve! It stays warm for a good 20 minutes thanks to that protective layer of cheese. Oh, the powers of cheese!
Recipe Notes:
Nutrition Information:
Life of Dozer
People have been wondering how Jeff is, our friendly local who lives at my local dog park (Bayview, in Sydney’s northern beaches), an official RecipeTin taste tester. He is doing well! This is how I start every weekend – coffee for Jeff, a ham and cheese croissant for his dog Cubby (sometimes Jeff gets a bite) and Dozer, waiting for scraps – until he gives up and gallops down to the beach to join his mates in the water!
Photo captured by Kevin of Unleashed Northern Beaches, a local photographer. Wonderful gift idea: voucher for a private pooch photo shoot!
Hi Nagi. Will this dish still b creamy if I dont use cheese ?
This recipe is super awesome!!! Thank you for sharing. It was a hit with my son and his friends and they are it all.
Love this! Especially the extra 2/3 c of milk. That’s what I’ve been missing in make ahead mashed potatoes. Was never sure if adding more butter or sour cream or what would do it. So thanks!
Loved this recipe. Made on the day and day ahead. Both worked well. Great change to plain mash.
I always add real salad cream to my mash, it gives it extra creamy/tartness. The butter is non-negotiable!
Is the bacon raw or cooked when added?
COOK BACON:
1. Place bacon in a cold non-stick pan over medium heat (no oil). As the pan heats up the bacon fat will melt. Once you see some melted bacon fat, turn the heat up to medium high and stir for 3 minute or until golden.
2. Drain on paper towels.
Hope that helps!
Definitely cooked bacon. It would make a nasty greasy mess if you didn’t cook it. I would just crumble it on top. 😃
What to use instead of bacon as do not eat red meat
I meant to say I do not eat any meat only occasionally chicken and fish ………..
Bacon is pork – the other white meat 🙂
Try crispy onion instead of bacon and omit the green onions and sprinkle with chopped parsley for colour.
I think it’s so thoughtful that people jump in & answer for Nagi. I’m sure she can’t get to every question when she’s got fans all over the world & tons of recipes, etc to do as well as the holiday season. And Dozer can’t forget him. Anyway thanks to all who answer other fans’ questions. Season’s greetings to all.
My favourite Blogger for sure. Recipes are always 5* and so delicious and easy to follow. I can hardly wait to get your cookbook. I just am not able to PIN your recipes. Can you help?
i have trouble if i use the little pin icon on the pictures. right under the title on the recipe card, theres options to pin, share on facebook, or email the recipe. thats what always works for me. if that doesnt work for you, maybe nagi can answer. good luck!
Hi Holly,
When I save Nagi’s recipes I just press the heart shape on the right side of the screen and it goes into “My Recipe Tin” which is located on the top left of the screen (on my iPad). Hoping this helps.
Hi Holly-tried that many times-no luck. It used to work but not anymore-2-3 months now.
oh man! im sorry 🙁
Thanks from Canada 🇨🇦 Holly, you tried.
Yum!! Oeeshi 🤓 Reminds me of potatoes romanoff that my mom used to make in the 1970s. Yours is new and improved.!
おめでとう omedeto NAGI and Dozer 🐾..all your hard work and taste testing is really really paying off. I’m so glad to have been a witness to it.
Domo arigato for being so generous with your time to those in need there with your recipetinmeals and unbelievably taking time to respond to so many of your followers.
All the best 🤩 from Canada 🇨🇦
I’m sooo proud of u N! With all of the hard work u put into your cookbook u deserve it! All of your yummy recipes that u conjure up week after week are always the best! Dozer is getting his spotlight now! Lol
I was wondering how Jeff was doing too and I’m happy that he’s doing good!
I hope u, Dozer and your family have a fantastic Thanksgiving N! 🦃
I’m excited to make this recipe for a dinner party we’re hosting tomorrow. One question – I couldn’t find any oven temperature. I’m assuming it’s around 325F.
It’s listed under Assemble—#1 says to preheat to 400.
Congratulations!! What an achievement! And. It’s well deserved!
Yuk does not appeal to me at all. Starchy melange
IT IS NOT AT ALL!! I am VERY sensitive to gluey mash and this is absolutely not at all. Because you don’t stir it at all once assembled!
I believe the reason your cookbook is selling so well all over the world is because your recipes are the best. They consistently taste the best, you don’t need to be a trained chef to make them, and you try so hard to involve all of us in your joy of cooking. You have fun; if you can, then we can at least try. And then there’s Dozer. I hope your cookbook sells millions of copies.
OMG this looks amazing and I will make this for xmas dinner 😉
I have ordered your book and I am looking forward to it.
During the pandemic (which we are still in) I was making a lot of your recipes since I was making more meals.
I truly enjoy your Facebook posts/emails on new recipes and of course DOZER!!
He is a lovely doggo and please give him lots of kisses from me (I live in Ottawa Canada).
I wish happiness/success/health for you this upcoming Christmas season (or whichever holiday season you celebrate).
Thank you for helping ALL of us during the pandemic, you helped so many people discover cooking again!!
Much love from Ottawa Canada.
Steve and Cashew (my orange/white tabby cat)
Dearest Nagi, congratulations and tremendous thanks and appreciation. Once again, you’ve made a very difficult year better. Providing affordable, first tier recipes in an easy to follow format seems daunting to me. Sending them out with such good humor and wit makes for a cheery good read whether or not the recipe is made. Creating a nonprofit that feeds people, let’s them know they matter and are important all the while being invested in your friends, your family and dear Dozer inspires hope and faith. You create space for dreams, a little self-belief, and positivity.
I am looking forward to receiving your cookbook. It is a testament to what one woman, with no family financial wealth to back her, can do. It is aspirational. Thank you for sharing your journey.
I love your comment. And you hit the nail on the head 🙂
I am so happy I discovered her Facebook posts which lead me to using her recipes!
Have a lovely holiday season!
Good morning Steven. I appreciate your kind response. Thank you! May your holiday season be warm, blessed and lovely.
Melinda
Love mashed potatoes!..we grew up on them. My Mom always put in garlic cloves, and raw onion when boiling the potatoes. It all just cooks and melts away when you mash everything…..what a great flavour it adds.
That sounds great; I’ll be trying that the next time I make mashed potatoes (after doing Nagy’s version, of course)!
Can’t wait to try this recipe out. Agree with your comment of weight over volume for cheese… but no weight given in recipe.
Lovely..I might do these!!Thank you
The step-by-step instructions give the oven temperature, but the recipe card does not. Perhaps you could update the card to include it.