Step 1

Preheat oven to 350F.

Step 2

Prepare frozen pierogies according to package directions for boiling. Drain. Arrange at the bottom of a 9x13 casserole dish.

Step 3

Add extra virgin olive oil to a large skillet over medium heat. Add onions, mushrooms and season with salt and pepper. Cook until the onions are softened, about 10 minutes. Add pasta sauce and stir to combine.

Step 4

Pour pasta sauce mixture over pierogies in the casserole dish. Cover with aluminum foil. Bake for 30 minutes.

Step 5

Remove from oven and top with Parmesan cheese. Serve hot.