Easy Pierogi Casserole with Kielbasa

This Pierogi Casserole turns frozen potato and cheese pierogies into an easy, hearty dinner. The pierogi are layered with browned kielbasa, sweet onions, and a homemade creamy cheese sauce, then baked until hot and bubbly. Since the pierogi go into the casserole straight from the freezer, there’s no need to boil or pan-fry them first. Add a little sour cream and sliced green onions on top before serving for a comforting dinner the whole family can enjoy.

Do I need to thaw or cook the frozen pierogi before baking them in the casserole?

No. Frozen pierogi go straight from the box into the baking dish. They cook through in the covered portion of the bake, steaming in the sauce, which is what keeps them tender. Thawing them first makes them sticky and hard to layer, and they can turn mushy by the time the casserole is done.

What Can I Substitute for Kielbasa?

You can replace the kielbasa with smoked sausage, cooked bacon, or ham. Cut your choice of meat into bite-sized pieces before adding it to the casserole. For a meatless version, skip the sausage and add sauteed mushrooms and cabbage, and use vegetable broth.

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Can I make this pierogi casserole ahead of time?

You can assemble the whole casserole several hours ahead, cover it and refrigerate. Add about 10 minutes to the covered baking time when it goes into the oven straight from the refrigerator. Hold the green onions until after it bakes.

Ingredient Notes

ingredient for Easy Pierogi Casserole with Kielbasa

Frozen potato and cheese pierogies: No need to thaw or cook them before assembling the casserole.
Kielbasa: Adds smoky flavor and makes this casserole hearty enough for dinner.
Sweet onion: Slowly cooking the onion in butter brings out its sweetness.
Butter: Used to cook the onions and form the base of the creamy sauce.
Garlic: Adds extra flavor to the kielbasa and sauce.
All-purpose flour: Thickens the chicken broth into a smooth sauce.
Chicken broth: Forms the base of the homemade cheese sauce.
Ground mustard: Adds a little sharpness that works well with the cheddar.
Paprika: Adds mild seasoning to the creamy sauce.
Salt and black pepper: Season the sauce to taste.
Sour cream: Makes the sauce creamy without using cream cheese.
Sharp cheddar cheese: Gives the casserole its rich cheese flavor and creates the melted topping.
Mozzarella cheese: Melts smoothly into the sauce.
Green onions: Add a fresh finish to the top of the casserole.

fork picking up Easy Pierogi Casserole with Kielbasa

How to Make Easy Pierogi Casserole with Kielbasa

Preheat the oven to 350°F. Spray a 9×13-inch baking dish with cooking spray then set it aside. Melt the butter in a large skillet over low heat then add the onions and allow them to soften and begin to caramelize.
Add the kielbasa and minced garlic to the skillet and allow it to brown. Stir frequently to make sure the onions don’t get too dark. About 3-4 minutes.
Sprinkle the flour over the onions and kielbasa until it is fully absorbed. Slowly pour the chicken broth and gently stir until the sauce begins to thicken. Stir in the ground mustard, paprika, pepper and salt until combined.
Remove the skillet from heat and add the sour cream, 1 cup of sharp cheddar and the mozzarella cheese.
Gently stir until the cheese is melted.
Add 12 pierogi into the bottom of the baking dish. Gently spread half of the kielbasa and sauce over the pierogi layer.
Layer the remaining 12 pierogi and then pour the remixing kielbasa and sauce, spreading out evenly.
Top with the remaining shredded cheddar. Cover the dish with aluminum foil tightly and place in the over for 25 minutes.
Remove the foil and continue to cook for 10-15 minutes until the casserole is bubbling and the cheese is melted.
Allow the casserole to set for a few minutes, then sprinkle the sliced green onions over the top. Serve and enjoy.