Soak the morels in the milk for at least 15 minutes. Take out, rinse a little and cut into small pieces. Pass the milk through a fine sieve (to filter out any grains of sand) and collect it.
Meanwhile cook the pasta al dente according to the instructions on the packet.
Dice the onion and fry in butter until translucent. Add the milk, the cream and the morels. Bring to the boil and reduce a little, then season with salt, pepper and broth to taste. If you like it thicker, you can also bind the sauce a little. Mix with the pasta and serve immediately.
I always cook this recipe by feeling, so the quantities are rather loosely to be seen. Here for about 2 people. Ribbon noodles are great as pasta. But even there, everyone should take their favorite pasta and amount.