Although this recipe suggests that Gratin Dauphinois is best served with rack of lamb, a perfectly roasted
leg of lamb would be equally happy as a table partner with the recipe below ... Nota Bene: You might be tempted to serve this dish with "Thanksgiving Turkey", but methinks that most traditionalists would prefer a simple baked potato (NOT wrapped and steamed in aluminum foil !) and Candied Yams or Sweet Potatoes.
BTW: There is a remarkable difference - both botanically and culinarily - between Yams and Sweet Potatoes.

Scalloped Potatoes
(Gratin Dauphinois - dit Chamonix)
© Chef “Tuckerton”

Dauphinois, Lyonnaise, Chamonix, Savoyarde - all of these distinctly different French potato dishes are translated into English as “Scalloped Potatoes.” Here follows, however, the real recipe for (so called) Potatoes Dauphinois or more correctly called Chamonix.
(“Proper” Dauphinoise according to some purists is made without cheese)


Select medium sized potatoes of the "boiling" variety:
About one per person.) Peel then and set aside covered with water.
[Baking potatoes are also satisfactory, but count one potato per every two persons.]
one wholemedium-sized clove of garlic
Prepare the "Gratin" pan (any oven proof shallow [1 or2 inches deep] rectangular baking dish will do):

1. Coat the bottom of the dish heavily with butter. Crush a whole clove of garlic and rub the inside of the dish with the mangled garlic clove. (Be somewhat aggressive when rubbing so that the garlic imparts its character into the butter and onto the dish itself.) Discard the garlic clove! (This dish demands only a whisper of garlic . . . the flavor imparted by rubbing the pan with garlic is quite sufficient.)

2. Slice the potatoes very thin (1/16th of an inch thick) either by hand or with a mandolin. Arrange the potato slices into the dish as three alternating single-slice layers. Season each layer with a sprinkling of salt, white pepper and a few grains of freshly ground nutmeg. The total thickness of the potatoes should be no more than 1/2 to 3/4 inch thick (it would be best to be closer to 1/2 inch than to 3/4 inch).

3. Cover the potatoes generously with heavy cream. Use just enough cream to cover all of the potatoes and to allow them slip around each other comfortably, BUT not so much that they’re "swimming." Sprinkle a small amount of grated Greyère cheese evenly onto the top of the potatoes and cream. Do NOT be tempted to use more than a gentle sprinkling of cheese !

4. Prepare a Bain Marie: Also pre-heat an oven to 350-400°F
Place a folded towel into the bottom of an aluminium 4 or 5-inch deep baking pan, then place the prepared dish of potatoes onto the towel into the baking pan and carefully add very HOT water up to one half of the depth of the gratin dish.

5. Place the Bain Marie into the preheated 350-400°F oven and bake for about 35-45 minutes until the cream is absorbed and reduced and the cheese is browned lovingly.
Serve at once; as thee perfect accompaniment with a rack of lamb !