Sprinkle chops with 1/4 tsp (1 mL) each of the salt and pepper.
In large skillet, heat 1 tbsp (15 mL) of the oil over medium-high heat.
In batches, brown chops, about 6 minutes. Transfer to plate. Drain any fat from pan.
In food processor with slicing blade, cut onions into 1/8-inch (3 mm) thick slices.
In same skillet, heat 1 tbsp (15 mL) of the oil over medium heat; cook onions, parsley, sugar and 1/4 tsp (1 mL) each of the remaining salt and pepper, stirring often, until onions are golden, about 20 minutes. Stir in vinegar.
Meanwhile, in food processor, slice potatoes.
In 12-cup (3 L) casserole, toss potatoes with thyme and remaining oil, salt and pepper.
Pour broth over top. Place pork chops and any juices on potatoes; cover with onions.
Cover and bake in 425F (220C) oven until potatoes are tender, 50 to 60 minutes.
Uncover and let stand for 5 minutes before serving.