Heat oven to 350° F. Heat 2 tablespoons of the oil in a large ovenproof skillet over medium-high heat.
Add plums, thyme leaves, ½ teaspoon salt, and ¼ teaspoon pepper. Cook, stirring occasionally, until plums soften and release their juices, about 3 minutes. Transfer to a bowl.
Return skillet to medium heat and add remaining oil. Season chops with ½ teaspoon salt and ¼ teaspoon pepper. Cook until browned on 1 side, about 5 minutes.
Turn, top each chop with 1 thyme sprig, and cook for 5 minutes more.
Spoon the plums around the chops and transfer skillet to oven. Roast until the pork is cooked through, about 5 minutes.
Divide the chops and plums among plates.