Cut the cooked, peeled potatoes into slices. Cut the leek into rings, roughly grate the carrots and blanch them together.
Mix the minced meat with the onions, breadcrumbs, 2 egg yolks, salt, pepper and chilli. Form small balls. Fry these in clarified butter for a few minutes on all sides.
Heat the crème fraîche and meat stock. Cook the gorgonzola in it to make a creamy sauce. Stir in 3 egg yolks. Season with freshly grated nutmeg.
Layer a layer of potato slices in the buttered baking dish. This is followed by a layer of leek and carrots. After another layer of potatoes, vegetables again. Pour cheese sauce over after every single layer. Finally, put the meatballs on top and bake in the preheated oven at 225 ° C (gas mark 4) for about 30 minutes.