Cook and mash some carrots or use any that you have left over from a previous meal.
Place a layer of carrots in an ovenprooof dish. Then add a layer of tomatoes (I sometimes add a squirt of tomato puree to thicken the juice up a bit. Then add a layer of grated cheese. Then repeat all of the above.
Put the bowl into the oven and bake until warmed through and the cheese has melted and gone brown, about 20 minutes.
I've also tried adding in swede and/or onions or whatever we have to hand.