ingredients
directions
Preheat oven to 375°F (190°C). Butter an 8-cup (2 L) shallow casserole dish; set aside.
In a saucepan, combine cream, Dijon mustard, salt and pepper. Bring just to steaming over medium heat. Remove from heat and whisk to combine; set aside.
Meanwhile, peel potatoes; cut into very thin slices. Peel and core apple; cut into very thin slices. Pour enough of the cream mixture into prepared dish to coat the bottom. Layer about one-third of the potato slices overlapping as necessary; top with half of apple slices. Pour over one-third of the cream mixture. Repeat layering, ending with potatoes and remaining cream mixture. Press down potatoes with a spatula to cover in cream.
Bake for about 1 hour, until potatoes are tender and top is golden. (Baked dish can be cooled, covered and refrigerated for up to 1 day. Reheat, covered with foil, in 325°F/160°C oven for about 50 min, uncover for the last 10 minutes to crisp top.) Sprinkle with cheese; broil for about 2 min or until golden. Let stand for 10 min.