Maybe I would try to make this for the family? It sounded intriguing. I began looking looking for a recipe to approximate the dish. I first had to try a variety of spellings. On of my first results was from Google Books, called Mneme's Place:Book One by Glenn P. Wolfe. I giggle at the last name and went on to read the passage in question on page 233:
Siltz, for sure. Whatever else the contents, mason jar up to the lid with shimmering gelatin studded with cubes of fatty pink pork. And, to go with the silts, slices of pumpernickel or a heel a rye bread.
This seemed pretty close to what my husband had described. And I could completely understand poring hot pork gelatin into mason jars since they'd be fine under the initial heat. And, even more promising, I now had at least one spelling to work with.
I looked for recipes all over the web that would match, but nothing under that name or variation of that name. Just looking for a pork gelatin dish, I found a likely candidate from a recipe site I wasn't familiar with. The contributor thankfully included his or her source material, a local publication called What's Cooking in Niles. When I went back to Google books to investigate this book found that it was published by a Greek Orthodox church in Niles, IL. The book, which I have not seen or held, was published in 1989 by the Holy Taxiarchai and Saint Haralambos Church, likely as a fundraising effort.
Of course I couldn't resist and I looked up the church right back into the search engine. When the little map automagically plotted to the right of the search results, it was I've never been but have poured over so many census records in that area that all the place names seemed all too familiar- outside Chicago. I plotted it on the full Google map and then turned on my Google Saved Places called Wolff genealogy. Right there in front of me were the 1930 homes of several members of the family, including Grandma Delores Wolff, within 10 miles of the church. I have no way of knowing if this was her recipe included, but I'd like to think that because they lived in that community, I might now have a recipe that may be a fair approximation of what she might of made.
By this time I don't know if this was originally a Greek dish pick dup by the Poles, or a Polish dish picked up by the Greeks or neither of the above scenarios. But I did find some commercial products listed here - looks like Polish to me. I didn't know how to pronounce Galaretka Wieprzowa, but I clicked listen to it on at the left window of Google Translate. With a new name, I found images that looked right on and a better(?) recipe under the Eastern European subheading.