Sweet Potato Gratin

Sweet Potato Gratin

The idea behind this sweet potato gratin was to creatively reinterpret a Thanksgiving favorite with a bit more sophistication. The ingredients used here preserve the dish’s natural Thanksgiving dignity, with the earthy character of sweet potatoes balanced by toasted marshmallows customary to holiday sweet potato dishes. This version is a little grown up, though, with herb-infused cream and smoky, salty bacon topped with toasted maple marshmallow crème.

Smoky Sweet Potato Gratin with Maple Marshmallow Crème

Serves | 8 to 10 |


  • 1 Tbsp butter, for greasing
  • 4 to 6 medium sweet potatoes, about 3½ to 4 lbs, peeled
  • 12 oz thick-cut bacon (such as Nueske’s), sliced into ¼-inch pieces
  • 3 cups heavy cream
  • 2 sprigs fresh thyme
  • 2 sprigs fresh sage
  • 1 bay leaf
  • freshly ground black pepper

Marshmallow Crème

  • 3 large egg whites, room temperature
  • ½ tsp cream of tartar
  • 2 Tbsp granulated sugar
  • 1/3 cup water
  • 2/3 cup maple syrup
  • ¾ cup light corn syrup
  • 1 tsp vanilla extract

| Preparation – Gratin | Preheat oven to 375°F. Butter a 9-inch-by-13-inch baking dish.

Slice sweet potatoes into 1/8-inch chips using a mandoline or sharp knife and add to a large bowl. Set aside.

In a medium frying pan, cook bacon over medium heat until crisp. Remove with a slotted spoon and let drain in a paper towel-lined bowl.

In a medium saucepan, combine cream, thyme, sage and bay leaf and scald milk over medium heat. Remove from heat and let steep, about 5 minutes. Remove herbs from the cream and pour over potatoes.

In a baking dish, lay potato slices in overlapping rows for the first layer. Season with pepper and about half of the cooked bacon. Continue layering potatoes with pepper and bacon, finishing the last layer with potatoes.

Pour remaining cream over layered potatoes.

Cover baking dish with foil and bake 40 minutes. Remove foil and bake another 15 minutes or until potatoes are fork-tender. Set aside while preparing maple marshmallow crème.

| Preparation – Marshmallow Crème | Preheat broiler to 500°F. In the bowl of a stand mixer fitted with a whisk attachment, or in a large bowl using a hand mixer with a whisk attachment, beat egg whites with cream of tartar until foamy, about 1 minute. Slowly add 2 Tbsp of sugar while mixing and continue beating egg whites until they reach soft peaks, about 4 to 5 minutes. Set bowl aside.

Combine 1/3 cup water, maple syrup and corn syrup in a small saucepan and place over medium heat. Bring mixture to a boil and remove from heat.

Slowly pour hot syrup into egg whites while continuously beating. Increase speed to high and continue beating for 5 to 7 minutes, until mixture gains volume and holds some shape. Add vanilla and mix to combine.

Pour marshmallow crème over sweet potatoes, and smooth over or create small peaks with a spatula by gently patting spatula over crème. (These peaks will darken more than the valleys of the crème, once under the broiler.)

In the broiler, place oven rack 6 to 8 inches away from the broiler element. Place dish under broiler until marshmallow crème has achieved desired toasted brown appearance, 1 to 2 minutes.