Pani cà Meusa Stand
If it's traditional regional cuisine I'll try it. Pani cà meusa is a local Sicilian sandwich. Cow spleen is sliced thinly and slowly stewed in lard and served on a burger style bun with grated caciocavallo cheese and a squeeze of lemon. You can also order it maritato "married", which comes topped with ricotta cheese as well
I had never tried spleen, but i like liver so I ordered one on the way home from a wine bar. It was OK, but it's not in my top ten late night snack experiences. It's popular though, there was a line-up at midnight.
Here is a video about a pani cà meusa stand in Vucciria Market