01 -
Heat the oven to 190°C / 375°F. Butter a 20 × 28 cm shallow baking dish with the measured butter.
02 -
Slice the potatoes evenly, about 3 mm thick. Do not rinse after slicing; the surface starch helps thicken the sauce.
03 -
Whisk cream, milk, garlic, salt, pepper and 50 g Parmesan.
04 -
Arrange the potato slices in overlapping layers in the dish. Pour over the cream mixture and press lightly so it runs between the slices.
05 -
Cover tightly with foil and bake for 35 minutes. Remove the foil, scatter with the remaining 30 g Parmesan and bake for another 20–30 minutes until golden and a knife slips easily through the centre.
06 -
Rest for 10 minutes, then scatter with parsley and serve. Refrigerate cooled leftovers within two hours and use within three days.