Peel and grate the vegetables, preferably with the food processor - otherwise you save yourself the gym ;-). Finely dice the shallot.
Mix the vegetables with half of the cheese and the shallot and season with sea salt and pepper, thyme and nutmeg.
Chop or finely dice garlic.
Mix the crème fraîche with the cream, add the garlic and egg and stir everything well. Season with sea salt, pepper and nutmeg.
Grease a baking dish and pour in the vegetables. Spread the cream crème fraîche on top, about 3/4 of the vegetables should be in the liquid. If there is not enough liquid, add some milk. Scatter the rest of the cheese on top.
Preheat the oven to 200 degrees.
Cover the baking dish loosely with aluminum foil and place in the oven on the lowest rail. After 30 minutes, remove the aluminum foil and bake the gratin for another 30-40 minutes, a light crust should appear.