Preheat oven to 375 degrees. Rub a 2-quart baking dish with garlic, then lightly butter. Layer potatoes in dish, overlapping slightly.
In a medium saucepan, combine cream, 1 1/2 teaspoons salt, 1/4 teaspoon pepper, and pinch of nutmeg; bring to a simmer. Pour enough cream mixture into dish to just cover potatoes; cover dish with foil. Bake until potatoes are tender when pierced with a paring knife, 40 to 45 minutes. Remove foil and continue to bake until top of gratin is golden, 35 to 40 minutes. Let rest 15 minutes before serving.
To save time, use a mandoline or a food processor with slicing disk to cut the potatoes.
Although this is rather time consuming it was well worth it. Overall, this is a pretty easy dish to make. It is rather tasty too. My kids love mashed potatoes but me not so much. I think this dish tasted better than mashed potatoes and the texture of having the sliced potatoes instead of mashed potatoes made all the difference. I did not peel the potatoes mainly because I was being lazy and I like to eat the skin. Will definitely try mixed in cheese next time.