Cheesy Pierogy lasagna

1.Preheat oven to 375ºF and grease a 9x13 inch baking dish with butter or nonstick spray. 2.Cook lasagna noodles according to package directions, and set aside. 3.In a large skillet add onion, butter, salt, and pepper. Saute on medium heat until soft, about 10 minutes. 4.Place 4 lasagna noodles in an even layer on bottom of baking dish. Layer ½ of total mashed potatoes on top of noodles, followed by ½ of the sauteed onions, and ½ cup of cheese. 5.Repeat with another layer of lasagna noodles, remaining mashed potatoes, sauteed onions and ½ cup cheese. 6.Top lasagna with remaining 4 noodles and 1 cup cheese. 7.Bake for 30 minutes or until hot and bubbly. Serve hot and enjoy!