Frico (potato and cheese pancake)

Halve the peeled potatoes into large chunks and put them in a pot of cold water with a generous pinch of salt.

Cook until fork tender, erring on undercooked, about 20 minutes. Cool slightly.

Dice the onion and saute in a little butter with a small pinch of salt. Set aside.

Cut the mozzarella into very small cubes, or grate it.

Mash the potatoes with a fork, leaving them somewhat chunky. Add the onion and plenty of black pepper.

Preheat light olive oil in the same non-stick skillet. Add the potatoes and the cheese and mix with a fork, stirring often for a few minutes until the cheese is almost fully melted.

Flatten and cook over moderate heat about seven minutes, turning the pan now and then, until the underside has a deep golden brown crust.

Lower the heat, loosen with a fork, slide onto a pizza pan and flip back into the skillet.

Cook another seven to ten minutes until the second side has a crust. Turn out onto a plate and let it cool toward room temperature so it sets.