Wow, who knew there was a Polish deli - and a good one - in Hillsborough. It's called Halinka Polish Deli and is in a strip mall at the corner of Route 206S and Amwell Road. I found it quite by accident but stopped in on Thursday to have a look. They have a terrific selection of Polish goods including the old standbys, kielbasa, pierogis, babka, chrusciki, etc. Most of the items are labeled in Polish only but the people in the store are very friendly and will spend time with you to figure out everything.
The deli also serves hot lunches every day of the week. What a great find! Unfortunately, their web site leaves a lot to be desired but I include it anyway.