Brown turkey on stove top adding onions during the last 3 minutes of cooking. I also season with some garlic powder.
Mix turkey and onions with the cream soup.
Spray a 9 x 13 inch pan with nonstick, then spread the turkey mixture in the bottom of the pan.
Layer the corn on top of the turkey, and finally spread the mashed potatoes on top of the corn. Bake covered for about 25 minutes at 350 degrees. During the last 5 minutes of cooking uncover the casserole and sprinkle with grated cheese.