Season the chops on both sides with salt and pepper.
Heat the oil in a large, heavy skillet over medium-high heat until hot. Add the chops and cook on one side until well browned; turn and brown other side. Transfer to a plate and set aside.
Put the onion in the pan and cook, stirring, until softened, about 5 minutes. Stir in the mustard and 1/2 tsp. pepper. Add the cabbage and apples, season lightly with more salt, and cook, stirring, for another minute. Add the beer, thyme, and stock. Bring to a boil and cook for about 5 minutes to intensify the flavors.
Return the chops to the skillet, burying them in the cabbage mixture. Cover the pan and simmer until the pork is just cooked through, about 15 minutes. Season to taste. Arrange the chops on plates and top with the cabbage.