Gratin of Japanese Sweet Potatoes

Here’s a recipe for anyone who’s still looking for a side dish on our national feast day. I made this a couple weeks ago for a dinner featuring Scherrer Zinfandels from Alexander Valley to uniform raves. Sweet potatoes/yams and zin are great partners at the table.

3 lbs. Japanese sweet potatoes, peeled and cut into 1/8” thick rounds
2 cloves garlic, sliced thin lengthwise
1 pt. Heavy cream
Softened butter
Couple handfuls of bitter greens (mizuna, arugula, rabe, etc.), chopped or torn, then wilted in olive oil to evaporate some liquid
Dry bread crumbs
Grated parmesan
Grated fresh ginger
Nutmeg
Cardamon
Pepper
Salt

Butter a large baking dish (I used a 9x12” ceramic lasagna pan). Line bottom of pan with a couple layers of sweet potato rounds (hint: save the best looking pieces for the top layer). Top with sliced garlic. Sprinkle with salt, cardamon, and fresh ginger. Add two more layers of sweet potato, top with bitter greens. Sprinkle with salt, fresh grated nutmeg, and fresh ground pepper. Add two more layers of sweet potato using up all remaining (hint: overlap the slices shingle-style on the top layer for more attractive presentation). Press down firmly to even out the thickness and reduce the air pockets. Season with salt and pepper. Top with dry bread crumbs and grated parmesan, and dot with butter.

If you’re transporting this to another location, stop here, wrap it up with aluminum foil and cook it at the final stop.

To bake, pour the heavy cream overall, and cover with foil. Bake in preheated oven for approximately one hour. Remove the foil after first 30 minutes to crisp the top.

Note: When I first made this dish, I added a layer of Gruyere cheese. But I the Japanese sweet potatoes so richly flavored and nutty (chestnut-like), the flavor of the cheese was a distraction. The cream and butter provide plenty of dairy richness on their own. Also, be generous in adding salt to bring out the flavors as the starches will absorb more than you think. I use about three or four pinches of kosher salt for each couple layers.

Happy Thanksgiving!