Cheesy Onion Mashed Potato Casserole

thetipsyhousewife
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A Make Ahead Masterpiece

Cheesy Onion Mashed Potato Casserole

Cheesy Onion Mashed Potato Casserole is a make ahead masterpiece made with savory, sautéed onions and cheese. Cottage cheese makes these potatoes extra cheesy and it bakes up light and fluffy to become the perfect side to any meat dish.

This Cheesy Onion Mashed Potato Casserole actually tastes very similar to the inside of some of my favorite pierogis. I love this casserole because you can assemble it the day before you need it and pop it in the oven while your roasted meat rests before slicing in.

These potatoes are perfect for a Sunday dinner but would also be a wonderful side to your holiday dinner. Serve this with my Standing Rib Roast recipe or my Beef Tenderloin.

In all honestly it would be great with any protein you serve or even on its own.

When I made this to photograph for the website, I ate it for a few days after and it was truly fantastic reheated in the microwave.

Cottage cheese and egg yolks

Cheese From A Cottage

I can already see the Facebook comments when I post this recipe… sigh…. but the cottage cheese in this recipe is what makes it great. Cottage cheese is great in lots of baked goods!

It adds creaminess and a great texture to anything baked. This is one of the main reasons I use it in my Stuffed Shells.

I like to use the Daisy Brand cottage cheese for my recipe because it seems to have the least amount of liquid in it. Tasting Table has a great article on using cottage cheese in other baking.

Cooked onions in the potato mixture

Onions Make It Great

I love the addition of the sautéed onions in this recipe. I always add a splash of soy sauce to my onions because it adds such a great layer of flavor.

These onion will sing in this Cheesy Onion Mashed Potato Casserole! You can add as many onions as you like.

More or less, just do you!

The finished casserole
Yield: 6 to 8 Servings

Cheesy Onion Mashed Potato Casserole Recipe

Cheesy Onion Mashed Potato Casserole

Cheesy Onion Mashed Potato Casserole is a make ahead masterpiece. Buttery mashed potatoes whipped with cottage cheese, sautéed onions, and cheddar cheese. Trust the process on this recipe and you will have the best mashed potato casserole that is the perfect side to any meat.

Ingredients

  • 1 large Sweet Onion
  • 4 (ish) large Russet Potatoes *you will want to have about 4 to 6 cups of potatoes when cut
  • 1/2 cup of Heavy Cream
  • 8 tablespoons of Butter + 3 tablespoons of Butter
  • Salt
  • Pepper
  • 2 teaspoons of Onion Powder
  • 2 teaspoons of Garlic Powder
  • 1/2 tablespoon of Soy Sauce
  • 1.5 cups of Cottage Cheese
  • 2 Eggs
  • 1 cup of Sharp Cheddar Cheese
  • Dried Parsley

Instructions

  • Peel the potatoes and cut them into larger, even chunks. Add to a pot and cover with water and add a 1/2 tablespoon of salt. Bring to a boil and boil until fork tender.
  • Dice the onion very small, add 3 tablespoons of butter to a skillet, and then add the onions. Sauté until golden brown. Season with the onion powder, garlic powder, black pepper to taste, and the soy sauce. Sauté again for a few minutes after adding the extras. Remove from heat.
  • While the potatoes boil, melt the 8 tablespoons of butter on low. Season with some salt, pepper, and dried parsley. When the butter is melted, turn off the heat and add the heavy cream.
  • Drain the potatoes and add them back to the pot, then add the cream and butter mixture. Mash the potatoes until creamy. Add the onions and mix well to combine. Taste and see if the potatoes need more salt.
  • In a separate bowl, add the cottage cheese. You want to have hardly any liquid from the cottage cheese so try to drain that before adding. Whisk the two eggs and add to the cottage cheese and mix well. Season with a pinch of salt and pepper.
  • Heat your oven to 350°. Spray a 9 x 13 casserole dish with a non stick spray of your choice or rub down with butter.
  • Fold the cottage cheese mixture into the mashed potatoes.
  • Top with the cheddar cheese and parsley.
  • **At this point the potatoes can be covered and refrigerated overnight, then taken out 30 minutes before baking, then baked according to the directions.
  • Bake for 35 minutes or until the casserole is "puffy," especially in the center, and the cheese is golden brown and bubbly. **please note that every oven bakes differently and to keep an eye on the bake time the first time you bake this in YOUR oven.
  • Serve immediately, these reheat really well also.
  • **to reheat, place in a cold oven, covered in a piece of foil. Turn the oven to 375° and once the oven reaches temp bake for about 15 minutes more and remove.
    • © thetipsyhousewife

    1 Comments

    • jan lucyk

      August 25, 2025 at 12:58 pm

      Very little moisture in the cottage cheese, then could/should you use dry cottage cheese ?

      Reply

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