Ingredients
Method
- Preheat your oven to 350°F. Lightly coat a 9x13-inch baking dish with nonstick cooking spray. Also spray one side of a large piece of aluminum foil (big enough to cover the dish) and set both aside.
- Arrange half of the frozen pierogies in a single layer in the prepared baking dish.
- Spoon half of the Alfredo sauce evenly over the pierogies.
- Scatter half of the sliced kielbasa over the sauce.
- Sprinkle half of the shredded mozzarella and cheddar cheeses over the kielbasa.
- Repeat the layering with the remaining pierogies, Alfredo sauce, kielbasa, and cheeses. Cover the dish with the prepared foil (sprayed side down) and bake for 20 minutes. Remove the foil and continue baking until the casserole is bubbly and heated through, about 20 to 25 minutes more. Garnish with sliced green onions before serving.
Nutrition
Notes
For a golden top, switch the oven to broil for the last 2-3 minutes after removing the foil. Let the casserole rest for 5-10 minutes before slicing to help the sauce set. Use freshly shredded cheese from a block for the creamiest texture. Leftovers can be stored in an airtight container in the fridge for up to 3 days; reheat in a 350°F oven or microwave. Substitute the kielbasa with cooked Italian sausage or omit for a vegetarian version. If you prefer a spicier kick, add a pinch of red pepper flakes to the Alfredo sauce. To make ahead, assemble the casserole (without the foil cover) and refrigerate for up to 24 hours; add 10 minutes to the covered baking time.
