This is an easier way to get the same taste of pierogies, some say even better! Not for the "low-fat" crowd -- this is comfort food in the way I was raised (in a Hungarian family). Smells wonderful cooking -- great for potlucks -- and can be used as a side or main course @ any meal.
I am a good cook; not a good photographer, so apologize for the bad picture. :)
Heat oven to 350 degrees. Grease a lasagna pan with either baking spray or butter.
Sautee onions in butter on medium heat for about 10 mins. or until soft, but not carmelized. Sprinkle w/ some salt.
Add the cream cheese to the mashed potatoes (add milk, butter & salt & pepper to your mashed potatoes, as normal) & mix until well blended.
Begin to assemble: Put half of the onions on the bottom of your pan. Then top w/ half of the lasagna noodles, a layer of the potato mixture, then 1/2 of the shredded cheese. Repeat so that you end w/ cheese on top. I add Hungarian paprika and more salt & pepper to the top of the final mashed potato layer. Bake in oven covered w/ alumninum foil (not tight so cheese doesn't stick, or spray foil w/ baking spray) for 30 mins, then remove foil for another 30 mins. Let sit for about 15 mins before you attempt to cut. Enjoy!