Directions

1. Place onion, butter and brown sugar into a large skillet over low heat. Cook, stirring occasionally, until the onions have caramelized, about 45 minutes.
2. Preheat the oven to 350 degrees F (175 degrees C). Coat a 9x13 inch baking dish with cooking spray.
3. Place a single layer of potato slices in the bottom of the prepared baking dish. Cover with a thin layer of onions. Drizzle some of the cream, and sprinkle some of the rosemary over the layer. Repeat layers four times ending with onions, cream and rosemary.
4. Bake for 1 hour in the preheated oven, or until top potatoes are golden brown and sauce is bubbling.