This recipe should be baked and served in individual casserole dishes. This is a very rich recipe and not intended for those on low-cal diets. If making in one large casserole, be sure not to layer the potatoes too thickly. Brought to you from Inn at Little Washington.
Peel onion as thinly as possible.
Peel the potatoes and slice as evenly as possible, about 1/8" thick.
In a 4 quart heavy-bottomed saucepan, melt the butter over medium heat.
Add the onion slices.
Stir with a wooden spoon and cook until the onions are wilted and translucent.
Add the cream and bring to a boil.
Add the potatoes, folding them into the cream with a rubber spatula to make sure each slice is well coated.
Add nutmeg and season with salt and pepper.
Simmer until the cream begins to thicken and the potatoes are almost tender.
They should still have some resistance to the bite. (Recipe can be completed to this stage well in advance. If you are not ready to proceed with serving the potatoes, remove them from the pan and store in a covered container in the refrigerator)
Preheat the oven to 375 degrees F.
In 6-8 shallow, oven-proof gratin dishes, OR individual casseroles, OR in one large Pyrex baking dish, spoon a layer of potatoes and cream mixture about 1 inch deep. (It is not necessary to grease the dishes first). The casseroles can be assembled to this point well in advance of baking. The potatoes will not discolor since they are already partially cooked.
Bake in the upper third of the oven at 375 degrees for 12-15 minutes, or until the tip of a knife slides easily into the potatoes and they are golden brown on top.
