Classic Potato Gratin

This potato gratin is absolutely classic,
and simplicity itself: no onions, no cheese topping,
just potatoes, bathed in butter and cream,
with a bit of garlic for oomph.

Ingredients:
3 1/2 to 4 pounds baking potatoes, peeled and thinly sliced
4 tablespoons butter, cut into small pieces
3 to 5 garlic cloves, chopped
Salt and pepper
1 cup heavy cream
2 tablespoons chopped fresh parsley, or chives, for garnish

Directions:
Place the sliced potatoes in a bowl with cold water to cover.
Leave for at least 30 minutes, or up to an hour.
Remove from the cloudy water, and dry with a clean towel.
Preheat the oven to 375 degrees F.
Butter the bottom and sides of a baking casserole,
about 3 1/2 inches deep, and large enough to fit
all the potatoes (very large).
Sprinkle about half the garlic along the
edges of the buttered sides of the pan.
Make a layer of potatoes, dot with butter pieces,
sprinkle with salt and pepper,
drizzle with a few spoonfuls of cream,
scatter a little garlic on top,
then repeat in this fashion until
all the potatoes have been used.
End the top with a dabbing of butter,
the last slosh of cream,
and a sprinkling of salt and pepper.
Bake for an hour to an hour and a half,
or until the potatoes are very tender
and have absorbed all the cream;
the top of the potatoes should be golden brown
with darker brown splotches here and there.
Raise the heat to 400°F for the last 10 to 15 minutes.
Serve in its own casserole, or dish up individual portions,
sprinkling each with a little chopped fresh parsley.