I love sweet potato casserole, but not the overly sweet brown sugar and marshmallow versions found on many Thanksgiving tables in the United States. The sweet potato dish I'm interested in is closer to a gratin, with a big push towards the savory to play off of the natural sweetness of the potatoes. To do this I use herbs, garlic, parmesan cheese and smoked paprika (or chipotle if I'm in the mood to add heat.) Read on for my recipe!
Sweet potatoes are naturally very sweet and baking them only intensifies that sweetness. According to Cook's Illustrated, the sugars in sweet potatoes develop up until their internal temperature reach 175 degrees, so a good way to enhance their sweetness is to slowly raise the oven temperature. I adopted this method for my gratin.
But I didn't want to end up with an overly sweet, marshmallow-y side dish. No disrespect to that venerable dish; it just wasn't what I was after. I wanted to play on the sweet with some savory flavors (and potentially a little heat.) So I infused the cream with shallot, garlic, fresh sage and rosemary, and added a crunchy topping of smoked paprika-infused breadcrumbs layered with parmesan cheese.
The resulting gratin is a wonderful contrast in flavors and textures, a rich, savory/sweet, creamy/crunchy delight. If you want to add a little spicy heat, substitute chipotle powder for the smoked paprika or add a pureed chipotle to the cream mixture. Gratin recipes are difficult to nail down, as many elements are out of our control. They really lend themselves to improvisational cooking as there's a lot of wiggle room: how deep and wide your pan is and how you stack your potatoes will determine how much liquid you will need; how finely you grate your parmesan with determine how much you use, etc. Please use this recipe as a guideline and feel free to adjust according to your circumstances.
Sweet Potato Gratin with Smoky Breadcrumbs
Serves 4-6 as a side dish
2 1/2 tablespoons butter, divided
1 small shallot, finely chopped (about 2 tablespoons)
2 large cloves garlic, finely chopped
1 1/4 cup heavy cream (can use 1/2 & 1/2)
3 sage leaves
1 bay leaf
Sprig rosemary or thyme (optional)
1 1/2 pound sweet potatoes, scrubbed
Freshly ground black pepper
For the breadcrumb topping:
1 cup rough, fresh breadcrumbs, made from stale bread
1/2 teaspoon smoked paprika or chipotle powder
1/2 cup grated Parmesan cheese
2 or 3 fresh sage leaves, finely chopped
Butter a gratin dish and set it aside. (I used a 6" x 10" oval.)
Melt about 1 tablespoon of butter in a small sauce pan. Add the shallots and cook until wilted, about 2 minutes. Add the garlic and cook another minute, or until fragrant. Add the cream and bring to a simmer. Turn off the heat, add the sage, bay, and any additional herbs, and let steep for 10 minutes.
Meanwhile, slice the sweet potatoes into 1/4 inch rounds and place into the gratin dish. You can do this either by piling them flat in layers, or by standing the potatoes up (as pictured above.)
Remove the herbs from the cream and pour over the potatoes. Jiggle the potatoes around a little to be sure that the cream seeps between them. Grind some pepper over the top. Place the gratin dish on a baking sheet to catch any spills and cover will aluminum foil. Place in a COLD oven, turn on the heat to 425 degrees and bake for 30 minutes.
Meanwhile, prepare the breadcrumbs. Melt 1 tablespoon of butter in a frying pan, add the crumbs and sauté until they just starting to color. Turn off the heat, add the smoked paprika (or chipotle powder) and a pinch of salt and stir.
After 30 minutes, take the gratin from the oven, remove the foil and sprinkle on the breadcrumbs, followed by the parmesan. Return to the oven and bake an additional 20 minutes, checking after 10, or until the breadcrumbs are browned and most of the liquid has been absorbed.
Remove from the oven and sprinkle with the fresh sage. Let cool a few minutes before serving.
• The breadcrumbs and the cream infusion can be done in advance. Just be sure the cream is warm, or cook the potatoes a little longer under the foil.
• This also makes a nice vegetarian lunch dish, served with a salad that contains strong flavors, such as arugula or endive, and a punchy, mustard-y vinaigrette.