This creamy baked potato gratin composed of thinly sliced potato, heavy cream, and hard cheese is an easy, festive side that can be made ahead of schedule. Parcook the potatoes in sauce until tender, then transfer them to a cast iron dish and top with plenty of cheese. Just pop the whole thing in the oven five to ten minutes before you’re ready to serve, flame cooking until the sauce bubbles and the cheese turns a beautiful golden brown. This recipe uses King Edward potatoes, which are soft and tender, but if you prefer a bit more bite in your gratin, try waxy varieties such as new potatoes, French fingerlings, Red Bliss, Jersey Royals, Adirondack Reds, Russian Bananas (potentially the best-named potato ever?) or others.