The Empress Diner has good homemade pastitsio. It's a huge portion. I don't think it's available every day, since it was listed on a dinner special menu. The diner is open late and serves the pastitsio late if there's any left. They also make a pretty good moussaka, also homemade, but the pastitsio is better.
2490 Hempstead Tpke.
East Meadow, NY