Season both sides of the ribs with salt and Essence. Place the ribs in a large glass rectangle-baking dish. Pour 3 cups of the cider over the ribs, cover with plastic wrap, and refrigerate for 24 hours.

Preheat the oven to 350 degrees F.

Remove ribs from the refrigerator and discard the marinade. Sprinkle the brown sugar over the flesh side of the ribs. Wrap tightly in two layers of aluminum foil, sealing the meat as tightly in the foil as possible, and set on a rimmed baking sheet. Place in the oven and cook for 2 1/2 hours, or until tender.   When checking for doneness be careful, there will be hot juices inside the foil.  Remove from the oven and unwrap the ribs.

While the ribs are cooling, transfer the cooking juices to a small pot.  Skim and discard fat that rises to the top.  Bring the juices to a boil and cook for about 15 to 20 minutes until reduced and syrupy.  Set aside.  The glaze will continue to thicken as it cools.  You can  add more apple cider if you need to thin it.

Preheat the grill to medium high.

Place the ribs on the grill, flesh side down, and cook for 6 to 8 minutes, turning the ribs every 2 minutes, or until the ribs are nicely marked.  Transfer to a serving platter.  Drizzle the glaze over the ribs and garnish with the green onions.  Serve hot.