Prepare mashed potatoes according to package directions for 4 servings. (You can also use regular mashed potatoes, if you're so inclined, but it takes longer.) Mash into bottom of 1.5 or 2qt dish. Place in oven at 350 degrees F for 25 minutes or until edges are a golden brown.
Brown hamburger and then add the remaining ingredients, except for cheese. Mix all together.