Place a wooden spoon with a 1cm thick handle sitting flat on a chopping board. Place a peeled potato alongside the handle of the spoon and slice through the potatoes at 2mm thickness allowing the blade of the knife to land on the handle of the wooden spoon thereby preventing the knife from cutting all the way through the potatoes. This will prevent the potatoes from falling apart and remain hinged at the base.
Give the potato a 90degree or ¼ turn with its edge still resting alongside the wooden spoon and continue making cuts at 2mm intervals. The potato will now have an almost hedgehog like appearance.
Loosen the texture of the cuts in the potato with your hands. Place some of the slivers of the garlic in between the cuts in the potato pushing them in until just 2-3 mm of the garlic is visible protruding through the cut surface of the potato.
Roll the potatoes in the clarified butter encouraging some of the butter into the cuts in the potato. Place on a roasting tray and put into the heated oven. Spoon 4-6 tablespoons of the butter over the potatoes in the tray.
Cook for 45 minutes and then increase the temperature to 200c and cook for a further 25 minutes. By then the potatoes should be crisp and golden on the surface. I usually baste the potatoes with some of the butter several times during the cooking.
Season with sea salt and pepper and serve as soon as possible.