Pit and cut the plums into 1 inch slices and set aside For the pork; Mix the salt, five-spice, and pepper in a small bowl and set aside. Pat the pork chops dry with paper towels and place them on a large plate or baking sheet. Rub oil all over the pork and then rub all over with the spice mixture. Set aside at room temperature for 30 minutes or cover and refrigerate for up to 24 hours. Make the plum sauce; Heat the 2 Tablespoons of olive oil in a medium saucepan over medium heat until shimmering then add the shallot, ginger, and garlic and cook, stirring occasionally, until softened, about 3 minutes. Add the remaining ingredients, stir to combine, and bring to a simmer. Reduce the heat to low and continue to simmer, stirring occasionally, until the plums are completely softened and falling apart, about 5 minutes. Transfer the mixture to a blender. Remove the small cap from the lid (the pour lid) and cover the space with a kitchen towel (this allows steam to escape and prevents the lid from popping off), then blend until smooth. Transfer to a serving bowl and set aside. For grilling the pork chops; Heat an outdoor grill to medium (about 350°F to 450°F). If the pork chops have been refrigerated, let them sit at room temperature for at least 30 minutes before grilling.Place the pork chops on the grill, close it, and cook until grill marks appear on the bottom, about 9 minutes. Flip the pork chops, close the grill, and cook until they're browned and an instant-read thermometer inserted next to the bone in the thickest pork chop registers 145°F, about 6 to 10 minutes more. Transfer the pork chops to a clean serving platter, tent loosely with foil, and let rest in a warm place for 5 minutes. Serve with the plum sauce.