Peel and cut potatoes into even-sized pieces. Boil in salted water until tender, then drain well.
Pass the hot potatoes through a ricer or food mill into a clean bowl.
Stir in the butter, salt, pepper, and Dijon mustard while the potatoes are still warm.
Fold in the mozzarella cheese cubes gently.
Dust the work surface with cornstarch and spread the potato mixture into a ½-inch thick rectangle on parchment paper.
Refrigerate until firm, then cut into portions.
Coat each portion in a layer of cornstarch, brushing off excess, then coat with grated Parmesan.
Pan-fry the pavés in butter until golden brown on both sides.
Finish in the oven if needed until heated through.
Make ahead
Potato pavé requires some effort and time on the front end, but is perfect for holidays and dinner parties as the vast majority of the work can be done in advance. Once the potatoes are peeled, sliced and soaked in a mixture of seasoned butter and cream, they’re layered in a loaf pan and baked until tender. At this point, the dish can be covered and refrigerated for up to 3 days. When you’re ready to serve, you’ll only need to slice the chilled block into pieces and sear until crisped.
