Yesterday I made a sweet potato casserole for a Circle K luncheon and it was delicious! I got the recipe from here and I definitely recommend giving it a whirl if you can.
We used about three sweet potatoes (from the farm market) for the dish. I'd say it takes roughly an hour and a half if you need to peel, cut, and boil the potatoes (instead of using canned). The plate was clean when we left the luncheon though so it was time well spent.