To be honest, there is no "salt flavored savory pie" in Catalan cuisine, at least not in my search.
On one hand, the closest thing to a traditional Catalan Halloween food is panellets, which is not exactly a Halloween food and doesn't look like a pie. On the other hand, the closest thing resembling this round shaped yellow colored (vegetable) pie is Crema Catalana, but that's a dessert made with egg yolk, sugar and milk. This thing here is more a quiche than a pie.
But hey, I'm probably over thinking it. It's a hoax and it works like a charm, people won't bother to search. Catalonia could be right next to Kreplachistan for all they care.