If your meal won't quite go the distance then a potato bake is the answer. I have had many at BBQ's in South Africa and Australia. We had one for dinner tonight when my meat pie was not quite enough for us.
Peel and slice potato and then microwave in oven/microwave proof dish. Pour some french onion packet soup on top (I only use a tiny bit as I don't like flavouring). Pour some mozarella or any other cheese you fancy and cream to cover. Mix it all up. Sprinkle some cheese on top and then put in an oven till bubbling and golden.