Roasted Sweet Potatoes With Horseradish Butter

Preparation

1. Step 1

   In a heavy-duty resealable plastic bag, combine butter, horseradish, parsley, dill, panko, lemon zest and juice, salt and pepper. Close the bag, pressing out most of the air. Mash everything together until well combined and smooth, then use a ruler or the back edge of a knife to scrape and work the butter to the bottom of the bag so it forms a log, rolling it as you go. Refrigerate for at least 2 hours to firm up, or up to 1 week.

2. Step 2

   Heat oven to 350 degrees. Prick sweet potatoes several times with a fork and wrap tightly in aluminum foil. Transfer to a baking sheet and roast until potatoes are tender, 45 minutes to 1½ hours, depending on the size of the potatoes. Once cool enough to handle, unwrap and slice into ½-inch-thick rounds (there is no need to peel unless you dislike the skins). Potatoes can be roasted up to 2 days ahead; wrap and chill, then slice them just before using.

3. Step 3

   Arrange rounds on a large rimmed baking sheet and count how many you have. Slice enough thin slabs of butter from the log so that you have one per potato slice, and place butter on top of potato slices.

4. Step 4

   Move the oven rack so that it's 4 inches away from the broiler. Bake potatoes at 350 degrees until they are heated through and the butter is softened, 5 to 15 minutes depending upon how cold the potatoes were. Adjust oven temperature to broil, and broil until the butter is golden brown at the edges, 2 to 4 minutes. Serve garnished with herbs and fresh horseradish if you like.