Cheesy Mashed Potato Casserole

mashed potato casserole recipe in a white dish

5 from 1 votes

Cheesy Mashed Potato Casserole

Cheesy Mashed Potato Casserole (also known as a mashed potato bake) is an incredible and well known side dish that takes stove top mashed potatoes to oven basked potatoes. Creamy, cheesy and completely easy to load up with tons of toppings, this mashed potato casserole even includes a crunchy panko crumb topping that will BLOW YOUR MIND. While potato side dishes really are perfect for dinner and a crazy good holiday side dish, do not discount leftover mashed potato casserole just for lunch as well. Cheesy mashed potato casserole is a fantastic substitute for regular mashed potatoes. With lots of shredded cheddar cheese and a light but crispy bread crumb topping, this is a homemade holiday side dish that will complement the season deliciously.

Prep Time10

Cook Time35

Total Time45

Course: Casseroles, Side Dishes

Cuisine: American

Servings:

Calories: 519kcal

Author: Trisha Haas - Salty Side Dish

Ingredients

Mashed Potato Casserole

3 lbs. russet potatoes peeled and cut into 1" chunks
1-1/2 cups milk
1/2 cup sour cream
4 tablespoons butter
2 teaspoons Dijon mustard
1 tablespoon minced garlic
salt and pepper
1 cup shredded cheddar cheese

Crumb Topping:

1/2 cup Italian bread crumbs
2 tablespoons butter melted

Instructions

Peel potato skins and cut into 1 inch chunks (this helps potatoes boil faster).
Add potatoes to a large stockpot and cover with water, at least 1" above the potatoes.
Heat on medium high and boil potatoes until tender, easily sticking a fork into them. This typically takes about 15 minutes.
Carefully drain excess water and return soft, warm potatoes to pan.
Directly on the potatoes, add milk, sour cream, 4 tablespoons butter, Dijon mustard and minced garlic.
Mix all ingredients together well and season with salt and pepper.
Preheat oven to 375.
Grease a 1-1/2 quart casserole dish with nonstick cooking spray.
Spoon potato mixture into casserole dish and spread evenly.
To the top of the casserole, add shredded cheese evenly over the potatoes.
In a small bowl, combine bread crumbs and 2 tablespoons melted butter. Mix well.
Sprinkle bread crumbs on top of cheese in dish.
Bake potato casserole for 20-25 minutes or until the center is hot. Keep in mind that all ovens heat at a different temperature so its important to watch your breadcrumbs.
Remove casserole from oven and serve while cheese is melty.

Notes

When boiling fresh potatoes

While Russet potato's are recommended for this potato casserole, any type of potato (red, yellow, blue etc.) can easily be substituted for casserole variations.
Typically it takes about 15 minutes for cut potatoes to properly boil but just test with fork. Once tender, remove and drain.

What kind of topping goes best with mashed potato casserole?

Personally I love cheesy mashed potatoes as is but there is something about a crispy topping that just takes this regular mashed potato recipe to a hold new (and totally unique) level.

Keeping it simple, panko crumbs are my very favorite choice, but I have been known to substitute Ritz Crackers, Italian Bread Crumbs, and even Lay’s potato chips (like my mom did on tuna casseroles) as I was growing up.

What other flavor variations go well with potato bakes?

Of course this is only one way to make Mashed Potato and Cheddar Cheese casserole. As you get to know the base recipe, it may be time to experiment with flavors and your side dish choices by adding garlic, bits of onion, chives, bacon pieces and even changing up the type of potatoes themselves.
I have shared this recipe with so many people and had family and friends taste it and everyone has an opinion on ways to make it even more perfect for the holidays.

Using left over mashed potatoes

Making mashed potato casserole is even easier when you have left over potatoes. Simply warm up any left overs in a sauce pan and start with added ingredients.

Can mashed potato casserole be made ahead of time?

Absolutely! You can prep and assemble this casserole all the way up to the panko crumbs, then wait till add those toppings till baking. This makes sure that the breading doesn’t soften in the fridge. As far as timing, the fridge makes casseroles extra cold, therefore either bringing the chill off by setting at room temp for about 15 minutes prior to baking is helpful, or add additional time as needed.

How long can a mashed potato casserole stay good?

If you have left overs, store in the fridge for up to 3 days. Please note that panko crumb topping may soften in the fridge.

Nutrition