Preheat the oven to 180C/350F
Peel and cut potatoes into cubes. Place in a large bowl.
Add all the other ingredients apart from the mozzarella. Mix.
Pour into a baking dish and place in the oven covered in tin foil for 1 hour or until the potatoes are tender.Remove form the oven and place the sliced mozzarella on the top. Put back in the oven for another 10 minutes or until golden.