Pierogi Casserole {or lazyman's pierogies}

I love this recipe for 2 reasons:

1. Both my kids like to eat this
2. I can use up leftover mashed potatoes {I mean- what else can you do with them?}

Really easy and really yummy {not quite as good as the real thing but close}
We like to put a dollop of sour cream on top.
I'm sure it's not super healthy but makes great leftovers.

The players:
10-12 potatoes boiled and mashed {or leftovers!}
3/4 Cheddar cheese, grated
2 1/2 sticks butter {I did cut them down alittle}
2 onions, finely diced
1 lb. lasagna noodles, cooked

Cook lasagna noodles, mash potatoes.  Add cheese to potatoes and beat with mixer.  Saute onion in butter until soft.  Add 1/3 of onion and butter to potato mixture and add salt to taste.  Generously butter a 13x9-inch dish, put a layer of noodles, layer of potato mixture; repeat, ending with noodles.  Pour butter and onion over all.  Cover with foil, bake at 350 degrees until heated through.

Enjoy!