01 -
Preheat the oven to 375°F. Boil sweet potato slices in a large pot until tender, approximately 10 to 15 minutes, then drain thoroughly.
02 -
Grease a baking dish and arrange half of the sweet potato slices evenly. Scatter half of the fresh cranberries over the potatoes.
03 -
In a bowl, combine heavy cream, brown sugar, cinnamon, salt, and pepper. Pour half of this mixture evenly over the layered sweet potatoes and cranberries.
04 -
Create a second layer with the remaining sweet potatoes and cranberries, then pour the remaining cream mixture over the top.
05 -
Sprinkle shredded Gruyère cheese and breadcrumbs evenly on the top layer.
06 -
Bake in the preheated oven 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.