Mix together the cubes of pork, the salt, the pepper, and the sage.
In a large skillet, heat the oil and brown the seasoned cubes of pork on 2 sides, being careful not to crowd them.
Toss the browned pork cubes into your slow cooker insert.
Once the pork has been browned, drain off all but about 2 Tablespoons of the fat, then dump in your sliced onions. Stir them around and allow to cook on medium for 3 minutes, until softened.
Pour the balsamic vinegar into the pan and scrape up any brown bits on the bottom.
Transfer the onions and all that good juice to the crockpot, giving them a good stir with the pork.
Clap on the lid, then set the slow cooker for 3 hours on ‘High’, or 6 hours on ‘Low’.
