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 plastic wrap and then wrap in aluminum foil. Place in the oven and cook for 3 to 4 hours. Remove from the oven and cool completely.
Preheat the grill.
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.
In a saucepan, over medium heat, melt the butter. Add the onions and apples. Season with salt and pepper. Saute for 2 minutes.
Add the remaining 1 cup of cider and the chicken and beef broth. Bring to a simmer and continue to cook until the mixture reduces by half, about 8 to10 minutes. Whisk in the cold butter. Garnish with green onions and serve ribs with the apple slaw on the side.
In a medium mixing bowl, combine all of the ingredients except the salt and white pepper. Mix thoroughly and season with salt and white pepper, to taste.