Preheat oven to 375 F and grease 9x13 inch baking dish with butter or nonstick spray.

Cook lasagna noodles according to package directions, and set aside.

In a large skillet add onion, butter, salt, and pepper. Sauté on medium heat until soft, about 10 minutes.

Place 4 lasagna noodles in an even layer on bottom of baking dish. Layer 1/2 of total mashed potatoes on top of noodles, follow by 1/2 of sautéed onions, and 1/2 cup of cheese.

Repeat with another layer of lasagna noodles, remaining mashed potatoes, sautéed onions and 1/2 cup cheese.

Top lasagna with remaining 4 noodles and 1 cup cheese.

Bake for 30 minutes or until hot and bubbly. Serve hot and enjoy!