Potato Gratin with White Cheddar Cheese

I got this recipe from my Aunt Mary. She made this on Thanksgiving and it was so good!!

2 1/2 cups whipping cream
3/4 cup finely chopped shallots
2 teaspoons chopped fresh rosemary
2 teaspoons salt
3/4 teaspoon ground black pepper
4 pounds russet potatoes, peeled, cut into 1/4-inch-thick rounds
2 cups grated sharp white cheddar cheese

Preheat oven to 375°F. Butter 13x9x2-inch glass baking dish. Whisk cream, shallots, rosemary, salt and pepper in medium bowl to blend. Place half of potatoes in prepared baking dish, overlapping slightly. Sprinkle with 3/4 cup cheese. Top with second layer of potatoes. Pour cream mixture over potatoes in dish. Sprinkle with remaining cheese. Cover with foil and bake 1 hour. Uncover and bake until top is golden brown and potatoes are tender, about 45 minutes longer. Let cool 10 minutes before serving.

I believe this originally came from the Epicurious website.