Heat the oil in a large skillet over medium-high heat. Sprinkle the pork chops with salt and pepper on both sides and cook, flipping once, until nicely browned and cooked to 150 degrees F or desired doneness, 5 to 7 minutes per side. Set the chops aside and reserve the skillet.
Pour the chicken stock into the skillet and scrape with a wooden spoon to lift any browned bits. Add the shallots and cook, stirring occasionally, until the stock is reduced by half, about 4 minutes. Whisk in the mustard and apple butter. Turn off the heat and continue whisking until the sauce coats the back of a spoon, about 1 minute. Season as desired with freshly cracked black pepper.
This pan sauce also goes well with seared steak or chicken.