Preheat oven to 400.

Season both sides of the pork chops with rosemary, salt and pepper.

Heat 1 teaspoon of olive oil in a large oven-safe pan over medium-high heat. Add pork chops and sear until browned with a nice crust, about 3 minutes per side.

Transfer pork chops to a pan and cover to keep warm. Pork chops will not be cooked through at this point.

Reduce heat to medium, add remaining two teaspoons olive oil to pan and add sliced onions. Cook, stirring occasionally, until onions are softened and slightly browned. Turn down the heat if they are starting to burn at all.

Season the onions with salt and pepper. Add apple cider vinegar.

Return the pork chops and any accumulated juices to the pan and nestle in among the onions. Spread a tablespoon of apple butter over each pork chop.

Transfer the pan to the oven and cook for 8-10 minutes, until the pork is almost cooked through. (The temp should be about 145 for medium-rare, after it's rested. Go to 155/160 for a more well-done pork chop.) The timing will depend on the thickness of your pork chops.

Remove the pan from the oven and let the pork chops rest for 5 minutes before serving.