Brown the pork: Season one side of the chops with salt and pepper. Heat the oil in a large skillet over medium-high heat. Place the pork, seasoned side down, into the hot pan. Season the other side while the pork is browning, about 1-2 minutes. Flip and brown the other side. Remove the meat from the pan and cover on a plate.
Cook the onions and apples: Reduce the heat to medium. Add both onions and the apples to the pan. Season with the herbs and salt and pepper. Cook for a minute, then stir in the apple cider vinegar. Cook until starting to soften, about 3 more minutes.
Deglaze the pan: Increase the heat to medium-high. Once the pan is sizzling hot, pour in the white wine, scraping the browned bits off the bottom of the pan. Add the chicken stock and bring to a boil, then cook until the sauce has reduced by half, about 4-5 minutes.
Finish the dish: Stir the mustard and maple syrup into the sauce. Place the pork back into the sauce and finish cooking for 2-3 minutes or until the meat is done. Stir in the butter and serve immediately.