A twist on the classic Italian dish Parmigiana bianca. Simpler to make as you use ready bought creme fraiche or sour cream. Make sure you buy the smoked ham for that delicious smoky flavour throughout the potato. This one has two types of cheese, the Parmesan for it’s strength and provolone for a more gooey, runny cheese. Yes you could substitute provolone cheese for a tasty cheese if you can’t find it. Make the dish ahead of time, slice it into wedges and reheat in oven covered in foil or in microwave. It needs to be hot, not warm. It’s not a side dish, it’s a meal, so serve it the a crisp mixed salad to offset the richness. Enjoy layered potato gratin with smoked ham.