01 -
Preheat oven to 375°F. Bring a large pot of water to a boil and cook the sweet potato slices until tender, about 10 to 15 minutes. Drain thoroughly.
02 -
Lightly grease a baking dish. Arrange half of the sweet potato slices in an even layer and sprinkle half of the cranberries on top.
03 -
In a bowl, combine heavy cream, brown sugar, ground cinnamon, salt, and black pepper. Pour half of this cream mixture evenly over the first layer.
04 -
Layer the remaining sweet potatoes and cranberries, then pour the remaining cream mixture evenly over the top.
05 -
Sprinkle shredded Gruyère cheese and breadcrumbs evenly over the top layer.
06 -
Place the dish in the preheated oven and bake for 30 to 35 minutes until the surface is golden brown and bubbling.
07 -
Allow the gratin to cool slightly for a few minutes before serving.