Prepare the ingredients: wash and chop the parsley, peel and cut the mushrooms.
Melt a little butter in a large non-stick pan, let the garlic brown, then add the mushrooms and parsley and cook over medium-low heat for about 10 minutes.
In the meantime, in another non-stick pan, heat a little oil and add the anchovies, breaking them into pieces and leaving them to cook over a low heat until they fall apart, so as to form a sort of anchovy paste.
Cook the pasta in plenty of lightly salted water already boiling.
Drain the pasta al dente, add it to the mushrooms and mix it with the anchovy paste and a little cooking water (if necessary), then, if necessary, add salt.
The pasta with mushrooms and anchovies is ready, serve it hot.