Baked Japanese Sweet Potato

The type of sweet potato known as
satsuma-imo has a dense, starchy flesh
and chestnut flavor that takes well to cream.

Ingredients:
4 pounds Japanese sweet potatoes, peeled
2 quarts (8 cups) heavy cream
5 ounces prosciutto, cut in large dice
1/2 bunch sage, tied with string
Salt and white pepper to taste

Directions:
Preheat oven to 350 F.
Using a mandoline, slice sweet potatoes about 1/8-inch thick.
Place sweet-potato slices in a heavy-bottomed pot and cover with cream. Add prosciutto and sage and season to taste.
Simmer over medium heat until tender, about 20 minutes.
With a slotted spoon, remove prosciutto and sage and discard.
Remove sweet potatoes from pot, reserving one cup of the cream.
Layer the potato slices evenly in an 8-by-12 baking dish.
Pour the reserved cup of cream over the potatoes
and let it settle for 5 minutes.
Place baking dish in oven for 15 minutes
or until potatoes are golden brown.