Step 1

Preheat the oven to 425°F. Cut thin slices lengthwise from the bottoms of the sweet potatoes to allow them to lie flat. Discard removed slices. Place the sweet potatoes, flat side down, on your cutting board. Cut down into each sweet potato to make crosswise 1/8-inch slices, leaving each sweet potato intact at the bottom. Arrange the prepared sweet potatoes in a 12-inch cast-iron or other ovenproof skillet.

Step 2

In a small bowl, stir together the melted butter, shallot, garlic, salt and pepper until combined. Spoon half of the butter mixture over the sweet potatoes and reserve the remaining butter mixture.

Step 3

Bake the sweet potatoes in the preheated oven for 35 minutes. Meanwhile, stir the parsley, thyme and sage into the reserved butter mixture. In a small bowl, toss together the bread crumbs and Parmesan.

Step 4

Remove the skillet from the oven. Spoon the remaining butter mixture evenly over the sweet potatoes. Sprinkle evenly with the bread crumb mixture. Return the skillet to the oven, and bake until the sweet potatoes are tender and the topping is golden brown, 10 to 12 minutes. If desired, top with toasted nuts. Editor's Tip: Let your sweet potatoes cool for 5 to 10 minutes before digging in. Sweet potatoes can trap some serious steam inside them.