Preheat your oven to 375°F (190°C).

Peel and slice the sweet potatoes, then boil them in water for 10-15 minutes until just tender.

Grease a baking dish and layer half of the cooked sweet potatoes followed by half of the cranberries.

In a bowl, mix the heavy cream, brown sugar, cinnamon, salt, and pepper, then pour half over the first layer.

Layer the remaining sweet potatoes and cranberries, then pour the rest of the cream mixture on top.

Sprinkle Gruyère cheese and breadcrumbs over the top.

Bake for 30-35 minutes until golden brown and bubbly.

Allow the dish to cool for 5-10 minutes before serving.