Preheat your oven to 375°F (190°C) and prepare your baking dish by greasing it.

Peel and slice the sweet potatoes thinly, then boil in a large pot for about 10-15 minutes until fork-tender.

Arrange half of the sweet potato slices in the greased baking dish, overlapping slightly.

Sprinkle half of the fresh cranberries over the sweet potato layer.

In a mixing bowl, combine heavy cream, brown sugar, cinnamon, salt, and pepper. Whisk until blended.

Pour half of the cream mixture over the layered sweet potatoes and cranberries.

Add the remaining sweet potato slices over the cranberries and then the rest of the cranberries.

Pour the remaining cream mixture over the top, then sprinkle with Gruyère cheese and breadcrumbs.

Bake in the preheated oven for 30-35 minutes until golden brown and bubbly.

Let cool for a few minutes before serving to allow layers to set.