Peel the potatoes and carrots and cut or slice them into very thin slices. Layer alternately in a baking dish and season each layer with salt, pepper and nutmeg. Mix the whipped cream with the sour cream, season again vigorously with pepper and salt. Pour this sauce over the vegetables and sprinkle everything with the grated cheese. Cook in the preheated oven at 200 ° C for about 70 minutes. Serve hot.