She said Zarosiak, not Zaroślak. :-)
Zarosiak - from rosić (to bedew, to drizzle), to cover with dew, with moisture.
Moi Krewni database lists only five people with this surname in contemporary Poland. But they all are in Nowy Targ county, quite probably in Piekiełko or nearby.
quite probably in Piekiełko
Oops, I meant Piekielnik
, not Piekiełko.