Cook the pasta in salted water according to the instructions.
Clean the leek, cut in half, wash and cut into narrow strips. Clean and wash the mushrooms, cut large heads in half and fry them brown in clarified butter. Add the leek and cook until translucent.
Drain the pasta, return it to the saucepan and mix with the vegetables.
Bring the cream with the wine to the boil and melt the coarsely grated cheese in it. If necessary, stir in the sauce thickener and bring to the boil. Season with salt, pepper and nutmeg.
Mix the cream sauce with the pasta and serve immediately.