Cavolo Nero and Potato Casserole | Hearty Gratin

Preheat the oven to 180 °C top/bottom heat. Thoroughly grease a baking dish with 10 g of the unsalted butter.

Peel the potatoes, wash them thoroughly, and slice them into thin slices (about 3–4 mm thick) using a mandoline or knife. Parboil in boiling salted water for about 5 minutes, drain, and allow the steam to evaporate briefly.

Remove the thick centre ribs from the cavolo nero, cut the leaves into bite-sized strips, and blanch in boiling salted water for 2–3 minutes. Shock in cold water and squeeze out well.