In a large pot, stir together all of the sugar, 3/4 cup of the vinegar and the 5 spices, then bring this mix to a boil.  Reduce the heat, simmer and stir for a few minutes until the sugar has completely dissolved, then carefully add in all of the saskatoons.

Bring this new mix back to a boil, reduce the heat again and cook and stir until the berries are thawed and jammy and most have burst.  While the berries are cooking, stir/whisk the cornstarch into the remaining 1/4 cup of vinegar in a small bowl, taking care to make sure all of the cornstarch is dissolved.  Use a spatula to scrape the cornstarch mix into the simmering berries and then stir until the chutney has come back to a boil and thickened up.  This will be obvious, and the juices should be clear.

As I mentioned, I skip the processing step but feel free to do as you please (use solid instructions to make sure your jars are processed safely and properly!).  I poured/scraped my chutney into 3, 500 mL sterilized jars, then sealed and labeled them and left them to sit on the counter to cool completely before checking/tightening the seals and popping them into the freezer.  Our current favorite use of Saskatoon Chutney is as a sidekick to Porchetta, as a chicken or pork sandwich topper, or with any grilled sausage.