Mashed Potato Gratin
Mashed Potato Gratin takes creamy, cheesy mashed potatoes and tops them with a crispy, buttery panko crust for a side dish that’s a step above the usual. It’s budget friendly, make ahead friendly, and a genius way to use up leftover mashed potatoes. You can even start with store bought to save time. Freezes beautifully and reheats like a dream. Made with pantry staples, it comes together in about 25 minutes and serves 12.
When I think of mashed potatoes, I think of the standard side everyone loves and nobody remembers. Reliable. Fine. A little forgettable.
Let’s switch things up for moment.
Take those same creamy potatoes, fold in cheese, and top the whole thing with a crispy buttery panko crust, and suddenly it’s the dish people go back for. It’s different without being fussy, and it doesn’t blow the budget or your evening.
You can even make it with store bought mashed potatoes if you want to cut a corner, and I fully support that.
It’s also a make ahead dream, it’s the best way I know to use up leftover mashed potatoes, and it freezes beautifully. That crispy top is the part everyone fights over. If you love an easy potato side, I have a few for you to try!
More Potato Sides
- Creamed Potatoes – simple creamy stovetop mashed potatoes
- Million Dollar Mashed Potatoes – crockpot mashed potatoes for a crowd
- Air Fryer Smashed Potatoes – crispy potatoes with easy toppings
- Joanna Gaines Sweet Potato Casserole — creamy casserole with pecans
This post may contain affiliate links. As an Amazon Associate, I earn from qualifying purchases at no additional cost to you. Read my disclosure policy.
See recipe card for complete information on ingredients and their quantities.
Ingredient Notes
Potatoes – Russets are the best here for that fluffy, creamy mash everyone loves. I use 5 large ones, roughly 3 pounds.
Sour Cream – Full fat, reduced fat, or low fat all work. Plain Greek yogurt is a great tangy swap.
Milk – I use 1%, but fat free works too. Substitute half and half if you want even creamier potatoes.
Cheese – I used Emmentaler (Swiss) this time, but Gruyere, cheddar, or mozzarella all work well. Pick your favorite. Something that melts well is even better.
Egg – One large egg, beaten and brought to room temperature first. It helps hold everything together for that gratin texture.
For more insider tips, tricks, and a behind the scenes look, follow me on Pinterest, Facebook, Instagram, & X.
How To Make Mashed Potato Gratin
- Heat the oven to 375°F. Peel and dice the potatoes, place them in a large pot, and cover with cold water. Add 2 teaspoons of salt.
- Bring to a boil over high heat and cook until the potatoes are fork tender. Drain and return them to the pot. Gently mash the potatoes, just until most of the large chunks are gone. Don’t overwork them.
- Add the milk, sour cream, cheese, beaten egg, and 4 tablespoons of butter. Gently fold to combine, and season with salt and pepper to taste. Spray a 9×13 baking dish with cooking spray and spread the potato mixture evenly inside.
- In a small bowl, toss the panko with the remaining 2 tablespoons of melted butter until well coated. Sprinkle over the potatoes. Bake at 375°F for 15 to 20 minutes, until the potatoes are hot and the top is golden brown. Serve warm.
For the full recipe and detailed instructions, please refer to the recipe card at the bottom of the post.
Storage & Reheating
Refrigerator: Store leftovers in an airtight container for up to 4 days.
Reheat: Bake in a 350°F oven for 15 to 20 minutes, until heated through. If the potatoes seem dry, stir in 1/2 cup of broth, water, or milk before baking to bring back the creaminess.
Freezer: Prep it (without the topping), wrap tightly in plastic, and freeze for up to 2 months. Thaw overnight in the fridge, top with panko, cover with foil, and bake as directed.
Make Ahead: Prep and refrigerate, covered, until you’re ready to bake. Leave the panko off until right before it goes in the oven so it stays crisp instead of soggy.
Variations
Different Cheese: Swap the Emmentaler for Gruyere, cheddar, mozzarella, or whatever’s your favorite. This is an easy dish to make your own with your favorite cheeses.
Richer Potatoes: Boil the potatoes in chicken broth instead of water for a deeper flavor.
Egg Yolks: Substitute 2 egg yolks for the whole egg for an even richer texture.
Loaded: Fold in crumbled bacon, chives, or green onion for a loaded baked potato twist.
Extra Creamy: Use 1/2 cup of the reserved potato water or warm milk when mashing.
Spicy: Stir in 1 tablespoon of creamy horseradish sauce to make these horseradish mashed potatoes.
Why Are My Mashed Potatoes Gluey or Gummy?
Gluey, gummy mashed potatoes come down to one thing: overworking them.
When you mash or mix potatoes too much, you break down the starch and it turns into a paste. Once that happens, there’s no fixing it. So the trick is to be gentle.
Cook the potatoes until they’re properly fork tender first, since undercooked potatoes tempt you into extra mashing. Then use a potato masher or a wide fork, not a mixer, and mash just until most of the large chunks are gone.
When you add the rest of the ingredients, fold them in gently and stop as soon as they’re combined. A few small lumps are better than a bowl of glue.
Frequently Asked Questions
Yes. Prep it, cover, and refrigerate until you’re ready to bake. Leave the panko topping off until just before baking so it stays crispy instead of soaking in.
Yes, up to 2 months. Prep it, wrap tightly in plastic, and freeze. Thaw overnight in the fridge, then top with panko, cover with foil, and bake as directed.
Absolutely. This is one of the best ways to use up leftover mashed potatoes, and store bought works great when you’re short on time.
Overworking them. Mash gently with a masher or fork just until the big chunks are gone, and fold in the other ingredients without overmixing. A mixer is the fastest way to turn them to glue.
I like Emmentaler or Swiss, but Gruyere, cheddar, and mozzarella all melt beautifully. Use whatever your family loves.
Stir in 1/2 cup of broth, water, or milk before reheating. It brings the creaminess right back.
Recipe Tips & Tricks
- Salt the cooking water so the potatoes get seasoned from the inside.
- Boil the potatoes in chicken broth instead of water for a richer flavor.
- Toss the panko with melted butter before topping so it browns faster and crisps up golden.
- Mash gently and fold the ingredients in without overmixing to avoid gummy potatoes.
- Leave the panko off until just before baking if you’re making it ahead, so it stays crisp.
This Mashed Potato Gratin recipe is creamy, cheesy, and topped with the best crispy panko crust. Make it for your next dinner or holiday table and watch it disappear ahead of the plain potatoes!
If you love this recipe as much as I do, please leave us a ⭐️⭐️⭐️⭐️⭐️ five-star review in the comment section below. Thanks!
Mashed Potato Gratin Recipe
Ingredients
- 5 large Russet potatoes approximately 3 pounds
- ½ cup sour cream
- ½ cup milk
- 1 large egg beaten
- 6 tablespoons butter divided 4 tbsp + 2 tbsp
- 1 cup panko crumbs
- 4 ounces shredded cheese I used Emmentaler this time
Instructions
- Heat oven to 375F. Spray a 9×13 baking dish with cooking spray to prevent sticking.
- Peel and dice the potatoes. Place in a large pot and cover with cold water. Add 2 teaspoons salt.
- Bring to boil over high heat and cook until the potatoes are fork tender. Drain and return potatoes to the pot. Reserve some potato water just in case!
- Gently mash the potatoes.
- Add the milk, egg, sour cream, cheese, and 4 tablespoons of butter. Mix to combine.
- Season with salt and pepper as desired.
- Spread the potato mixture in the prepared baking dish.
- In a small bowl, combine the panko with 2 tablespoons of melted butter. Mix until the panko is coated well.
- Sprinkle the buttered panko crumbs over the mashed potatoes.
- Bake at 375F for 15-20 minutes or until the potatoes are hot and the top is golden brown.
- Remove from the oven and serve warm.
Notes
- Salt the cooking water so the potatoes get seasoned from the inside.
- Boil the potatoes in chicken broth instead of water for a richer flavor.
- Toss the panko with melted butter before topping so it browns faster and crisps up golden.
- Mash gently and fold the ingredients in without overmixing to avoid gummy potatoes.
- Leave the panko off until just before baking if you’re making it ahead, so it stays crisp.
Nutrition
Here are more Side Dish recipes:
- 1 Hour Soft and Buttery Dinner Rolls from Hezzi-D’s Books and Cooks
- Apple Stuffing Muffin Cups from Blogghetti
- Braised Red Cabbage with Cranberry and Juniper from Palatable Pastime
- Carrot Peanut Slaw from A Kitchen Hoor’s Adventures
- Creamy Kale and Corn from Magical Ingredients
- Garlic Parmesan Green Beans from Cookaholic Wife
- Mashed Sweet Potatoes with Bacon & Chives from Sweet Beginnings
- Roasted Brussel Sprouts with Bacon, Pecans, and Cranberries from Jen Around the World
- Roasted Butternut Squash & Rice Salad from Jolene’s Recipe Journal
- Skillet Corn from Devour Dinner
- Whole Roasted Squash from Art of Natural Living
©TakeTwoTapas.com. Content and photographs are copyright protected. Sharing of this recipe is both encouraged and appreciated. Copying and/or pasting full recipes to any social media is strictly prohibited.
