Cut the mushrooms into pieces. Finely dice the onion and dice the salami as well.
Heat the butter and fry the mushrooms and onions in it. Fry the salami briefly. Season with salt and pepper. Dust with the flour and sauté briefly. Pour in the broth and milk, bring to the boil and simmer over low heat for 4 - 5 minutes.
Cook the gnocchi according to the instructions on the packet, then drain on a sieve. Season the mushroom sauce with salt, pepper and nutmeg. Mix the gnocchi and sauce and place in a baking dish. Sprinkle with cheese and grill under the preheated grill of the oven for 5 - 10 minutes until golden brown.