Par freeze the pork for 20 minutes.
Slice the pork into ½" cubes.
Season the pork with the salt, sage and thyme.
Add the cheese and toss to combine.
Chill in the fridge until ready to grind, at least 1 hour.
Meanwhile, place the components of your meat grinder in the freezer to get them cold.
When ready to grind, run the pork mixture through the grinder until all of the pork is ground.
Chill again for at least 3 hours.
Clean, dry well, and place the components of your meat grinder back in the freezer.
Toss the ground pork mixture with the blueberries and maple syrup.
In a small pan, cook a tablespoon of the mixture to test for seasoning. Adjust to your taste.
When ready to stuff the sausage, slide the casing over the sausage extruder completely.
Working carefully, start running the pork mixture through the grinder.
Slide the casing down, giving about 2 inches as the first bit of sausage comes out.
Using your hands, guide and shape the sausage to fill the casings, pulling the casing down to fill.
When a few inches remain stop and tie off both ends.
Slide the next casing on and repeat the process until all of the pork sausage has been stuffed.
Cook immediately or save for later. Par freeze the sausage on parchment paper lined baking racks before sealing to freeze.