Pat pork chops dry and season with salt and pepper.
Heat oil in a 12-inch nonstick skillet over moderately high heat until hot but not smoking, then sauté chops until browned on both sides, about 10 minutes total.
Stir together cider and brown sugar and add to skillet. Simmer, uncovered, turning chops once, until meat is almost cooked through, about 3 minutes.
Transfer chops to a plate.
Add vinegar and mustard seeds to sauce and boil, stirring to scrape up any brown bits, until reduced to about 1/3 cup, about 5 minutes. Return chops with any juices on plate to skillet and simmer until meat is just cooked through and sauce is slightly thickened, about 2 minutes.