Put into a mixer, in this order:
Robiola cheese, porcini mushrooms, sliced onion, salt, pepper, oil.

With an immersion blender, in five minutes, create a soft cream, of which the thickness you can adjust by using more or less olive oil.

Add salt and pepper as required.
In separate plates, delicately place the slices of culatello, a leaf of red radicchio and a few spoonfuls of porcini mousse.