How to Make It
In a mortar, crush the crushed red pepper with the peppercorns, juniper berries, allspice berries and bay leaves. Transfer the spices to a large pot and add the water, cumin, soy sauce, small onion, garlic and thyme. Submerge the pork roast in the brine, meat side down. Cover and refrigerate for 24 hours, turning the roast over once.
Meanwhile, in a skillet, heat the oil. Add the sliced onions and cook over moderate heat, stirring occasionally, until softened, 20 minutes. Season with the cloves and salt and pepper. Add the brown sugar and cook over moderately low heat until the skillet is dry, 10 minutes. Add the balsamic vinegar and orange zest and cook over moderately low heat, stirring occasionally, until the marmalade is very thick, 30 minutes. Transfer the marmalade to a bowl. Cover and refrigerate.
Remove the pork roast from the marinade 1 hour before cooking and let stand at room temperature. Pat the pork roast dry with paper towels and wipe off any spices sticking to it. Season the pork with salt and place it on a rack in a roasting pan.
Preheat the oven to 450°. Cook the pork roast for 15 minutes, then reduce the oven temperature to 375° and cook it for about 1 hour and 10 minutes longer, until an instant-read thermometer inserted in the thickest part of the roast registers 140°. Transfer the roast to a carving board and let rest for 15 minutes. Carve the roast between the bones into chops. Transfer the chops to plates and serve with the onion marmalade.