Rehydrate the porcini mushrooms with 1/2 cup hot water.
Bring 3 liters of water to boil for the pasta.
Meanwhile prepare the sauce by heating the oil over medium heat in a large pan. The pan needs to be large enough to hold the noodles once cooked.
Add the garlic and hot pepper flakes, cooking them until garlic turns golden.
Add the white mushrooms, raise the temperature to medium-high and continue to cook.
Cook pasta in boiling water according to package directions.
Squeeze the liquid from the porcini, reserving it for the sauce.
Chop the porcini and add to the pan.
Pour the soaking liquid through a fine sieve into the pan.
Add sage and cook for 5 minutes.
Drain the pasta (do not rinse) and toss into the pan with the mushroom sauce while hot.
Add boconcini cheese, parsley and serve.