Preheat the oven to 200 °C. Peel the potatoes and slice 3 mm thin slices into them, but not all the way to the bottom. The easiest way to do this is to put the potato in a spoon ad use that to guide you. Place the potatoes in a greased ovenproof dish.
Sprinkle the potatoes with salt and pepper and finish with breadcrumbs. On each potato, place a knob of butter. Roast the potatoes in the oven for roughly 45 minutes, or until soft inside, whilst dousing them with fat from the dish every ten minutes.