Cook the spaghetti in salted water until al dente.
Sauté the minced meat in the olive oil and add the leek cut into rings.
Pour about 1/4 l of milk, add the 2 kinds of cheese and the cream, melt and let everything simmer a bit. Season with salt, pepper and marjoram. If the sauce becomes too thick, add some more milk. Serve the sauce with the drained spaghetti.
