Preheat the oven to 350 degrees.
Arrange the potatoes in a cast-iron pan or ovenproof casserole in at least 3 layers, alternating each layer with the blue cheese and salt and pepper. In a pot, bring the cream to a boil and pour over the potatoes. Cover the pan with plastic wrap and foil.
Place the pan in the oven and put a cookie sheet underneath in case the cream boils over. Cook until the potatoes are tender when stuck with a fork and the cream has reduced, 45 minutes. Remove the cover and cook for 10 minutes to brown the top. Remove from the oven and let cool for 15 minutes before serving.