Slice the mushrooms and the shallots.
Cut the Ardennes ham into fine slices.
Slowly heat the butter in a casserole.
Fry the sliced shallots, add the ham, the mushrooms and allow to brown slightly.
Then pour in the fresh cream and bring to the boil.
Allow to chill for a few minutes.
Then add the egg yolk and the mustard.
Homogenize the mixture.
Season with salt and pepper.
Cook the pasta, present in the serving dish and cover with the sauce and the parmesan.