Cheesy Mashed Potato Casserole
Looking for a decadent side dish for entertaining? This cheesy mashed potato casserole has it all: velvety yellow potatoes, gooey mozzarella, salty Pecorino, and a crunchy Panko topping. It won’t be easy to stop at one serving!
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Ingredient-Stretching Tip: If you have remaining mozzarella, use it for this sun-dried tomato omelette.
Many moons ago, I first made Giada’s baked Parmesan mashed potatoes with breadcrumbs and became an instant fan. Although not an everyday recipe, it’s a relatively easy and inexpensive side dish to “whip up,” and it’s designed to impress.
I did, ultimately, decide to change it up a bit, mainly by using yellow potatoes for a creamier texture and replacing standard breadcrumbs with Panko for a crispier topping. This cheesy mashed potato casserole complements steak, roast chicken, a pork roast, or even grilled shrimp.
The luscious potatoes and crunchy Panko topping make it difficult to eat just one serving. On the other hand, this recipe is quite rich, so a little goes a long way. This cheesy mashed potato casserole not only tastes delicious but also freezes well.
Most of all, it makes an excellent side dish if you’re looking for something relatively easy to make but memorable to serve to guests. Whether those guests are friends or family, they’ll love this comforting casserole!
Why You’ll Love This Cheesy Mashed Potato Casserole
- Inexpensive: The only real expense here is the fresh mozzarella and Pecorino Romano, but you can often find fresh mozzarella on sale, and you can buy Pecorino Romano in bulk at places like Costco and freeze it.
- Virtually foolproof: If you’re new to cooking, this recipe doesn’t require much skill. If you can boil water, you can boil potatoes! After that, this recipe only involves mashing the potatoes before mixing a few ingredients together.
- Feeds a large crowd: This casserole can be easily doubled, but even the original recipe can feed at least eight people.
Key Ingredients
- Yellow Potatoes: These potatoes make this casserole creamier than Russet potatoes.
- Fresh Mozzarella: The fresh variety is more tender than part-skim and will melt beautifully here.
- Pecorino Romano: This sharp cheese elevates the flavor, so I highly recommend using it in this recipe.
- Panko Breadcrumbs: These add much more crunch than standard breadcrumbs.
See the recipe card below for more information on ingredients and quantities.
How to Make This Cheesy Mashed Potato Casserole
- Peel and boil the potatoes: Boil the peeled potatoes in a large pot of salted water until fork tender. Drain and place them back in the pot.
- Make the Panko topping: Mix together the Panko, melted butter, Pecorino, garlic powder, salt, and pepper in a small bowl. Set aside.
- Mash the potatoes: Using a potato masher, mash the potatoes until smooth. Stir in the butter, milk, mozzarella, Pecorino, salt, and pepper.
- Prepare the casserole: Pour the potatoes into a 1.5-quart casserole dish (could also be a little bigger), and smooth out the top. Sprinkle the Panko mixture over the top of the mashed potatoes.
- Bake: Bake the casserole on the oven’s middle rack, uncovered, at 400F for 20 minutes.
- Finish: Garnish the casserole with minced fresh parsley.
Pro Tips
- Prepare beforehand: You can prepare this casserole ahead of time. Assemble it but do not bake. Cover and store in the refrigerator for up to 24 hours. Remove it from the fridge, and let it sit on the counter for 30 minutes before baking. The casserole may need to cook for longer than the 20 minutes per the recipe instructions, so you may want to cover the casserole for the first 10 minutes to prevent the Panko breadcrumbs from burning.
Variations & Substitutions
-Use Yukon Gold potatoes instead of yellow potatoes.
-Garnish with additional fresh herbs like chives.
-Replace the garlic powder in the Panko topping with grated fresh garlic for more sharpness.
Recipe FAQs
Technically, yes, but yellow or Yukon Gold potatoes will yield creamier, more velvety potatoes, which is a highlight of this casserole recipe.
I don’t recommend doing so. Bits of potato skins in this casserole dish won’t be pleasant. If you don’t want to peel the potatoes with a peeler before boiling them, you can peel the skins off after boiling them. Just let them cool first so they’re easier to handle.
It should, but if it doesn’t, just pop it under the broiler for a couple of minutes. But watch it carefully so it doesn’t burn!
Storage
Refrigerator: Store in the refrigerator in an airtight container for up to 3 days.
Freezer: Store in the freezer for up to 2 months. Defrost in the refrigerator before reheating.
Reheat: Reheat in the oven until warmed through, uncovered to help crisp up the Panko topping. You can also reheat in the microwave, but the Panko won’t get crispy again.
More Potato Recipes
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Cheesy Mashed Potato Casserole
Ingredients
For the Potatoes
- 2 pounds yellow potatoes peeled and cut into quarters (Note 1)
- 2 and ½ teaspoons kosher salt divided (2 teaspoons + ½ teaspoon)
- 4 tablespoons unsalted butter cut into small pieces
- 1 cup whole milk (Note 2)
- ¾ cup fresh mozzarella shredded or finely chopped
- ½ cup Pecorino Romano cheese grated
- ¼ teaspoon black pepper ground
- Italian flat-leaf parsley handful, minced
For the Panko Topping
- ½ cup Panko breadcrumbs
- 2 tablespoons unsalted butter melted
- 1 tablespoon Pecorino Romano cheese grated
- ½ teaspoon garlic powder
- ⅛ teaspoon kosher salt
- Pinch black pepper ground
Instructions
- Boil the potatoes in a large pot of water with 2 teaspoons of kosher salt until fork tender, stirring occasionally, about 20 minutes. Drain the potatoes, then transfer them back to the pot you boiled them in.2 pounds peeled and cut yellow potatoes2 teaspoons kosher salt
- Meanwhile, prepare the Panko breadcrumbs by mixing all the ingredients together in a small bowl. Set aside.½ cup Panko breadcrumbs2 tablespoons melted butter1 tablespoon grated Pecorino½ teaspoon garlic powder⅛ teaspoon kosher saltPinch of ground black pepper
- Preheat the oven to 400F.
- Using a potato masher or handheld mixer, mash or blend the potatoes until smooth. Stir in the butter, milk, mozzarella, Pecorino, remaining ½ teaspoon kosher salt, and pepper.4 tablespoons melted butter1 cup whole milk¾ cup shredded mozzarella½ cup grated Pecorino½ teaspoon kosher salt¼ teaspoon ground black pepper
- Pour the potatoes into a 1.5-quart casserole dish. You don't have to coat the dish with any butter because there's already enough butter in the potatoes that they won't stick. Smooth the top with a spatula so the potatoes are even. Top the potatoes with the seasoned Panko breadcrumbs.
- Place the casserole dish on the oven's middle rack and bake for 20 minutes. If the top doesn't brown, place it under the broiler for a bit, but watch it carefully! Garnish the casserole with the minced parsley.Handful minced flat-leaf Italian parsley
