Clean and wash the leek and mushrooms. Cut the leek into slices. Halve mushrooms if necessary. Cook pasta in salted water for 8-10 minutes. Drain well afterwards. Heat the oil in a large pan.
Brown the minced meat in it until crumbly. Add leek and mushrooms and also fry. Deglaze with stock and cream. Bring to the boil and thicken with sauce thickener. Season with salt, pepper and paprika. Stir cheese into the sauce.
Wash parsley, dab dry and chop. Serve spaghetti with the sauce. Sprinkle with parsley.