Preheat oven to 180 C. Lightly grease an 8-cup capacity baking dish. Combine butter, cream and garlic in a bowl and stir to combine.
Arrange a layer of potato slices over the base of the dish then drizzle over a third of the cream mixture then season and sprinkle with a third of the cheese. Repeat to make three layers. Top with rosemary and thyme.
Cover and bake covered with foil for one hour. Then cook for another 20 minutes uncovered until cooked through and golden on top.