Preheat the oven to 400°F. In a small bowl stir together the kosher salt, dried thyme, allspice, garlic powder, and pepper. Remove the pork rib roast from the brine and pat dry. Rub the pork with 1 tablespoon olive oil and the spice mixture.
Heat the remaining olive oil in a wide skillet or braiser over medium high heat. Add the pork roast and sear on all sides until golden brown. Remove from the heat. Set the pork aside.
In the braiser or a roasting pan, scatter the sliced onions, apples, and dried apricots. Nestle the pork roast on top of the fruit. Pour 1 cup chicken broth in the pan and then place the pork in the oven to roast.
In a small saucepan melt the butter over medium high heat. Add the apricot jam, apple cider vinegar, kosher salt and allspice. Heat until the jam is melted. Whisk together and then remove from the heat.